Answer:
5 pounds
Step-by-step explanation:
Given that:
Amount of gift card = $80
Cost of coffee per pound = $8.24
Amount left in the card = $38.80
To find:
Number of pounds of coffee bought = ?
Solution:
Let the number of pounds of the coffee bought = [tex]x[/tex] pounds
Cost of 1 pound = $8.24
Cost of [tex]x[/tex] pounds = $8.24 [tex]\times x[/tex]
Writing the equation as per question statement:
[tex]80 - 8.24x = 38.80\\\Rightarrow 80 - 38.80 = 8.24x\\\Rightarrow 8.24x = 41.2\\\Rightarrow x = \dfrac{41.2}{8.24}\\\Rightarrow \bold{x = 5\ pounds}[/tex]
Therefore, 5 pounds of coffee was bought.
Use the Chain Rule to find the indicated partial derivatives. w = xy + yz + zx, x = r cos(θ), y = r sin(θ), z = rθ; âw âr , âw âθ when r = 4, θ = Ï2
Answer:
δw/δr = 4π
δw/δθ = -8π
Step-by-step explanation:
Given the following functions
w = xy + yz + zx, x = r cosθ y = r sinθ, z = rθ where r = 4 and θ = π/2
We are to find δw/δr and δw/δθ
δw/δr = δw/δx•δx/δr + δw/δy•δy/δr + δw/δz•δz/δr
δw/δx = y+z
δx/δr = cosθ
δw/δy = x+z
δy/δr = sinθ
δw/δz = y+x
δz/δr = θ
Substitute the given values into the formula
δw/δr = (y+z)cosθ+(x+z)sinθ+(y+x)θ
Substitute the value of x, y and z in terms of theta into the resulting function
δw/δr = (y+z)cosθ+(x+z)sinθ+(y+x)θ
δw/δr = (rsinθ+rθ)cosθ+(rcosθ+rθ)sinθ+(rsinθ+rcosθ)θ
Substitute r = 4 and θ = π/2
δw/δr = (4sinπ/2+4π/2)cosπ/2+(4cosπ/2+4π/2)sinπ/2+(4sinπ/2+4cosπ/2)π/2
Note that cos π/2 = 0 and sinπ/2 = 1
δw/δr = (4+2π)(0)+(0+2π)(1)+(4(1)+4(0))π/2
δw/δr = 0+2π+4π/2
δw/δr = 2π+2π
δw/δr = 4π
For δw/δθ
δw/δθ = δw/δx•δx/δθ + δw/δy•δy/δθ + δw/δz•δz/δθ
δw/δx = y+z
δx/δθ = -rsinθ
δw/δy = x+z
δy/δθ =rcosθ
δw/δz = y+x
δz/δθ = r
Substitute the given values into the formula
δw/δθ = (y+z)-rsinθ+(x+z)rcosθ+(y+x)r
Substitute the value of x, y and z in terms of theta into the resulting function
δw/δθ = (y+z)-rsinθ+(x+z)rcosθ+(y+x)r
δw/δθ = (rsinθ+rθ)-rsinθ+(rcosθ+rθ)rcosθ+(rsinθ+rcosθ)r
Substitute r = 4 and θ = π/2
δw/δθ = (4sinπ/2+4π/2)-4sinπ/2+(4cosπ/2+4π/2)4cosπ/2+(4sinπ/2+4cosπ/2)(4)
Note that cos π/2 = 0 and sinπ/2 = 1
δw/δθ = (4+2π)(-4)+(0+2π)(0)+(4(1)+4(0))(4)
δw/δθ = -16-8π+0+4(4)
δw/δθ = -16+16-8π
δw/δθ = -8π
Which number lines have points that represent additive inverses? Check all that apply.
===================================================
Explanation:
Choice B is one answer because -2 and 2 are additive inverses that add to -2+2 = 0
Choice D is a similar story. We have -5+5 = 0
In general, if x is some number then -x is its additive inverse. So we can say x+(-x) = 0 or -x+x = 0. In short, additive inverses add to 0.
Answer:
B and D
Step-by-step explanation:
What are the steps in solving the equation 4(2x + 3) = 10x?
Answer:
Step-by-step explanation:
Distributive property, subtraction, division
4(2x + 3) = 10x
8x + 12 = 10x
12 = 2x
6 = x
david noticed that 49=7, what are other numbers between 1 and 100 have exactly three factors
A rectangular solar panel has a length of 11 inches shorter than 4 times it’s width if the perimeter of the panel is 218 inches what are the dimensions of the panel
Colin, Sara and Gordon share some sweets in the ratio 2:5:3. Colin gets 26 sweets. How many sweets are there altogether?
Answer:
130
Step-by-step explanation:
Ratio is 2:5:3. Colin get 2/10 of the sweets so 26/x=2/10. Use the butterfly method to get 260=2x. Divide both sides by 2 and get x=130/
A solid is formed by adjoining two hemispheres to the ends of a right circular cylinder. The total volume of the solid is 10 cubic centimeters. Find the radius of the cylinder that produces the minimum surface area. (Round your answer to two decimal places.)
Answer:
[tex]r = 1.34[/tex]
Step-by-step explanation:
Given
Solid = Cylinder + 2 hemisphere
[tex]Volume = 10cm^3[/tex]
Required
Determine the radius (r) that minimizes the surface area
First, we need to determine the volume of the shape.
Volume of Cylinder (V1) is:
[tex]V_1 = \pi r^2h[/tex]
Volume of 2 hemispheres (V2) is:
[tex]V_2 = \frac{2}{3}\pi r^3 +\frac{2}{3}\pi r^3[/tex]
[tex]V_2 = \frac{4}{3}\pi r^3[/tex]
Volume of the solid is:
[tex]V = V_1 + V_2[/tex]
[tex]V = \pi r^2h + \frac{4}{3}\pi r^3[/tex]
Substitute 10 for V
[tex]10 = \pi r^2h + \frac{4}{3}\pi r^3[/tex]
Next, we make h the subject
[tex]\pi r^2h = 10 - \frac{4}{3}\pi r^3[/tex]
Solve for h
[tex]h = \frac{10}{\pi r^2} - \frac{\frac{4}{3}\pi r^3 }{\pi r^2}[/tex]
[tex]h = \frac{10}{\pi r^2} - \frac{4\pi r^3 }{3\pi r^2}[/tex]
[tex]h = \frac{10}{\pi r^2} - \frac{4r }{3}[/tex]
Next, we determine the surface area
Surface area (A1) of the cylinder:
Note that the cylinder is covered by the 2 hemisphere.
So, we only calculate the surface area of the curved surface.
i.e.
[tex]A_1 = 2\pi rh[/tex]
Surface Area (A2) of 2 hemispheres is:
[tex]A_2 = 2\pi r^2+2\pi r^2[/tex]
[tex]A_2 = 4\pi r^2[/tex]
Surface Area (A) of solid is
[tex]A = A_1 + A_2[/tex]
[tex]A = 2\pi rh + 4\pi r^2[/tex]
Substitute [tex]h = \frac{10}{\pi r^2} - \frac{4r }{3}[/tex]
[tex]A = 2\pi r(\frac{10}{\pi r^2} - \frac{4r }{3}) + 4\pi r^2[/tex]
Open bracket
[tex]A = \frac{2\pi r*10}{\pi r^2} - \frac{2\pi r*4r }{3} + 4\pi r^2[/tex]
[tex]A = \frac{2*10}{r} - \frac{2\pi r*4r }{3} + 4\pi r^2[/tex]
[tex]A = \frac{20}{r} - \frac{8\pi r^2 }{3} + 4\pi r^2[/tex]
[tex]A = \frac{20}{r} + \frac{-8\pi r^2 }{3} + 4\pi r^2[/tex]
Take LCM
[tex]A = \frac{20}{r} + \frac{-8\pi r^2 + 12\pi r^2}{3}[/tex]
[tex]A = \frac{20}{r} + \frac{4\pi r^2}{3}[/tex]
Differentiate w.r.t r
[tex]A' = -\frac{20}{r^2} + \frac{8\pi r}{3}[/tex]
Equate A' to 0
[tex]-\frac{20}{r^2} + \frac{8\pi r}{3} = 0[/tex]
Solve for r
[tex]\frac{8\pi r}{3} = \frac{20}{r^2}[/tex]
Cross Multiply
[tex]8\pi r * r^2 = 20 * 3[/tex]
[tex]8\pi r^3 = 60[/tex]
Divide both sides by [tex]8\pi[/tex]
[tex]r^3 = \frac{60}{8\pi}[/tex]
[tex]r^3 = \frac{15}{2\pi}[/tex]
Take [tex]\pi = 22/7[/tex]
[tex]r^3 = \frac{15}{2 * 22/7}[/tex]
[tex]r^3 = \frac{15}{44/7}[/tex]
[tex]r^3 = \frac{15*7}{44}[/tex]
[tex]r^3 = \frac{105}{44}[/tex]
Take cube roots of both sides
[tex]r = \sqrt[3]{\frac{105}{44}}[/tex]
[tex]r = \sqrt[3]{2.38636363636}[/tex]
[tex]r = 1.33632535155[/tex]
[tex]r = 1.34[/tex] (approximated)
Hence, the radius is 1.34cm
The radius of the cylinder that produces the minimum surface area is 1.34cm and this can be determined by using the formula area and volume of cylinder and hemisphere.
Given :
A solid is formed by adjoining two hemispheres to the ends of a right circular cylinder. The total volume of the solid is 10 cubic centimeters.The volume of a cylinder is given by:
[tex]\rm V = \pi r^2 h[/tex]
The total volume of the two hemispheres is given by:
[tex]\rm V' = 2\times \dfrac{2}{3}\pi r^3[/tex]
[tex]\rm V' = \dfrac{4}{3}\pi r^3[/tex]
Now, the total volume of the solid is given by:
[tex]\rm V_T = \pi r^2 h+\dfrac{4}{3}\pi r^3[/tex]
Now, substitute the value of the total volume in the above expression and then solve for h.
[tex]\rm 10 = \pi r^2 h+\dfrac{4}{3}\pi r^3[/tex]
[tex]\rm h = \dfrac{10}{\pi r^2}-\dfrac{4r}{3}[/tex]
Now, the surface area of the curved surface is given by:
[tex]\rm A = 2\pi r h[/tex]
Now, the surface area of the two hemispheres is given by:
[tex]\rm A'=2\times (2\pi r^2)[/tex]
[tex]\rm A'=4\pi r^2[/tex]
Now, the total area is given by:
[tex]\rm A_T = 2\pi rh+4\pi r^2[/tex]
Now, substitute the value of 'h' in the above expression.
[tex]\rm A_T = 2\pi r\left(\dfrac{10}{\pi r^2}-\dfrac{4r}{3}\right)+4\pi r^2[/tex]
Simplify the above expression.
[tex]\rm A_T = \dfrac{20}{r} + \dfrac{4\pi r^2}{3}[/tex]
Now, differentiate the total area with respect to 'r'.
[tex]\rm \dfrac{dA_T}{dr} = -\dfrac{20}{r^2} + \dfrac{8\pi r}{3}[/tex]
Now, equate the above expression to zero.
[tex]\rm 0= -\dfrac{20}{r^2} + \dfrac{8\pi r}{3}[/tex]
Simplify the above expression in order to determine the value of 'r'.
[tex]8\pi r^3=60[/tex]
r = 1.34 cm
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The recently released iPhone XS Max comes in three different storage sizes: 64GB, 256GB, and 512GB. The price of the 64GB phone is $1,099. If prices were proportional to the phone's storage size, how much would the 256GB phone and the 512GB phone cost
PLEASE HELP
Evaluate 6 + 10v – 8w when v=4 & w= -2
Answer:
6 + 10v – 8w = 62
Step-by-step explanation:
Given the expression
6 + 10v – 8w
as
v=4w=-2substituting the values in the expression
6 + 10v – 8w = 6 + 10(4) - 8(-2)
= 6 + 40 + 16
= 62
Quinzels earn 1254 each month his total deductions is 20%
Answer:
I believe its $250.80
Step-by-step explanation:
Because 20% of 1254 is 250.8
A proportional relationship is shown in the table below:
x:
0
1.3
2.6
3.9
5.2
y:
0
1
2
3
4.
What is the slope of the line that represents this relationship?
Graph the line that represents this relationship.
(13−0)
= 10/13
(10−0)
13,10
Slope of the given line is [tex]\frac{10}{13}[/tex] and the equation of the line is [tex]10x - 13y = 0[/tex].
What is the slope of a line passing through two points?The slope of a line(m) that passes through points (x, y) and (x, y) is
[tex]m = \frac{y_{2} - x_{1}}{x_{2} - x_{1}}[/tex]
The given line passes through points (0, 1.3) and (0, 1).
Therefore, slope of the line is
[tex]m = \frac{y_{2} - x_{1}}{x_{2} - x_{1}} = \frac{1 - 0}{1.3 - 0} = \frac{10}{13}[/tex]
Now, the line passes through the point (2.6, 2).
Putting this equation in slope-intercept form, we get:
[tex]2 = \frac{10}{13}(2.6) + c\\c = 2 - 2\\c = 0[/tex]
The equation of the line will be:
[tex]y = \frac{10}{13}x\\10x - 13y = 0[/tex]
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What is the slope of the line? PLEASE HELP!
What is the common difference between successive terms in the sequence? 0.36, 0.26, 0.16, 0.06, –0.04, –0.14
Answer:
-.1
Step-by-step explanation:
I’ll give the brainlest answer! Is this relation a function? Please help
Answer:
show me the choices
Step-by-step explanation:
so i qnswer ir
PLEASE HELP
A car dealer offers a 15% discount off the list price x for any car on the lot. At the same time, the manufacturer offers a $1500 rebate for each purchase of a car.
a. Write a function f(x) to represent the price after the discount is applied.
b. Write a function g(x) to represent the price after the rebate is applied.
Suppose the list price of a car is $19,000. Use a composite function to find the price
of the car:
C. if the discount is applied before the rebate;
D. if the rebate is applied before the discount
Answer:
A) f(x) = 0.85x
B) g(x) = x - 1500
C) g(f(x)) = $14650
D) f(g(x)) = $14875
Step-by-step explanation:
A) The list price is x and a 15% discount is applied.
Thus;
f(x) = x - 15%x
f(x) = 0.85x
B) We are told that the manufacturer offers a $1500 rebate for each purchase of a car.
Thus, the function g(x) to represent the price after the rebate is applied is;
g(x) = x - 1500
C)if the discount is applied before the rebate, the function is;
g(f(x))
Now,
f(x) = 0.85(19000)
f(x) = 16150
g(x) = x - 1500
Thus;
g(x) = 16150 - 1500
g(x) = $14650
D) If discount after rebate, then we have; f(g(x))
g(x) = 19000 - 1500
g(x) = 17500
f(g(x)) = 0.85(17500)
f(g(x)) = $14875
Anthony receives $12 in allowance every week.He currently has $492 saved.How many weeks has he been saving?
Answer:
He has been saving for 41 weeks.
Step-by-step explanation:
492 is the total, we need to divide 492 by 12 to get how many weeks, 41 is the answer
A large farm tractor costs $98,424. If a farmer makes 36 equal payments, how much is each payment
Answer:
$2734
Step-by-step explanation:
$98,424 / 36 = $2734
Given f(x) = 2x2 + 4x - 3 and g(x) = 5x - 2, find f(x) + g(x).
Must show all work to receive credit! Show your work in the box below.
Answer:
9x-3
Step-by-step explanation:
2x2=4
4+4x-3
4x-1
5x-2
Add them together
4x-1+5x-2= 9x-3
What is the diference between the
largest and the smallest 4 digit numbers
largest 4 digit number : 9999
smallest 4 digit numbers : 1000
Difference = 9999 - 1000 = 8999
Let's estimate 534–395.
(a) Round each number to the nearest hundred.
534 rounds to
395 rounds to
(b) Subtract the rounded numbers.
I
Answer:
A)
534 rounds to 500
395 rounds to 400
B) 100
Step-by-step explanation:
A)
534 rounds to 500 because the next digit 3 is less than 5 which means that you round down.
395 rounds to 400 because the next digit 9 is greater than 5 which means that you round up.
B)
500-400=100
Hope this helps! :)
The graph of an absolute value function opens up and has a vertex of (0, -3).
The domain of the function is
The range of the function is
Answer:
domain (-∞, ∞)
range [-3,∞)
Step-by-step explanation:
domain is the x value and range is the y value. Since its an absolute value the y value rises from both sides of the x value in a 45° angle.
A bell tolls every 30 minutes on the
hour and at half past the hour. How
many times does the bell toll
between the times of 11.45a.m. and
3.10p.m.?
37 % of $2927 is what
Answer:
1082.99
Step-by-step explanation:
2927 - 100%;
x - 37%;
=> x = (37*2927)/100 = 1082.99
what fraction is equivalent to 0.56
Answer:56/100
Step-by-step explanation:
The fraction equivalent to decimal number 0.56 is, 14/25
What is a fraction?Fraction is a mathematical term, which represents the portion or sub-parts of the whole thing. Basically, It has two parts: numerator and denominator.
Numerator is a number which lies on the top side, it indicates the number of equal parts taken and denominator is on the bottom side, it indicates the equal parts of the whole number.
Given that,
The decimal number 0.56
The equivalent fraction number = ?
For converting it into fraction,
We have to multiply and divide given number by 100
Now,
⇒ 0.56 x(100/100)
⇒ 56/100
Further, it can be solved
⇒ 28/50
⇒ 14/25
Thus, the equivalent fraction is 14/25
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Linear, exponential or neither?
y= 3x² + 2x + 4
A linear
B exponential
C neither
Answer:
C
Step-by-step explanation:
neither.
linear equations have constant slope. They take on the form of something like y= mx + b
exponential equations have a variable in the exponent. An example of this y= 3^x.
This is a polynomial equation - specifically a quadratic.
PLSSSSSSSSSSSSSS HELPPPP MEEEEEEE! ANSWER MY OTHER QUESTION!!!!
Answer:
Step-by-step explanation:
huh??
Marty swans 36 yards in 42 seconds. If he continues to swim at the same rate, how long will it take him to swim 500 yards
Find the equation of the line that is parallel to the given line and passes through the given point.
y = −4x + 7; (9, 5)
The equation is y =__________.
Answer:
y= 4 x
Step-by-step explanation:
y =4x − 7
Choose a point that the parallel line will pass through.
(0 , 0 )
Use the slope-intercept form to find the slope.
Tap for fewer steps...
The slope-intercept form is
y = m x+ b , where m is the slope and b is the y-intercept. y = m x + b
Using the slope-intercept form, the slope is
4 . m = 4
To find an equation that is parallel to y = 4 x − 7 , the slopes must be equal. Using the slope of the equation, find the parallel line using the point-slope formula.
( 0 , 0 ) m = 4
Using the point-slope form
y − y 1 = m ( x −x 1 ) , plug in m = 4 , x 1 = 0 , and y 1 = 0 .
y − ( 0 ) = ( 4 )( x − ( 0 ) )
Solve for y.
Subtract 0 from y .
y = ( 4 ) ( x − ( 0 ) )
Subtract 0 from x .
y= 4 x
HOPE THIS HELPS!
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Help please!!!!
What is the absolute value of the number indicated on the number line below?
A. -2/3
B. -3/5
C. 3/5
D. 2/3
Answer:
b
Step-by-step explanation:
it is 3 out of 5 ticks over to the left
Which of these expressions is the simplified form of the expression (Sin(x)/1-cos^2(x)) tan(x/2)?
Edge 2020
Answer:C
1/1+cos(x)
Step-by-step explanation:
Simplifird form of the given trigonometric expression will be,
[sinx / (1 - cos²x)] × tan(x/2) = 1 /(1 + cosx)
Simplification of a trigonometric expression:
Given expression in the question,
[tex]\frac{\text{sinx}}{1-\text{cos}^2x}\times \text{tan}(\frac{x}{2})[/tex]
= [tex]\frac{\text{sinx}}{\text{sin}^2x}\times \text{tan}(\frac{x}{2} )[/tex]
= [tex]\frac{1}{\text{sin}x}\times \frac{\text{sin}(\frac{x}{2})}{\text{cos}(\frac{x}{2} )}[/tex]
= [tex]\frac{1}{\text{2sin}\frac{x}{2}\text{cos}(\frac{x}{2} ) }\times \frac{\text{sin}(\frac{x}{2})}{\text{cos}(\frac{x}{2} )}[/tex]
= [tex]\frac{1}{\text{2cos}^2{\frac{x}{2} }}[/tex]
Use the identity → ([tex]2\text{cos}^2x=1+\text{cosx}[/tex])
= [tex]\frac{1}{1+\text{cos}x}[/tex]
Hence, [tex]\frac{\text{sinx}}{1-\text{cos}^2x}\times \text{tan}(\frac{x}{2})=\frac{1}{1+\text{cosx}}[/tex] will be the answer.
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