2x-3y=7 and y=3x-7 how do you solve this using subsitution
[tex]2x-3y = 7~~~....(i)\\\\y = 3x -7~~~....(ii)\\\\\\\text{Substitute}~ y = 3x -7~ \text{in equation (i):}\\\\\\2x-3(3x-7) = 7\\\\\implies 2x -9x + 21 =7\\\\\implies -7x = 7 -21\\\\\implies -7x = -14\\\\\implies x = \dfrac{-14}{-7} = 2\\\\\\\text{Substitute x = 2 in equation (ii):}\\\\y=3(2) -7 = 6 -7 = -1\\\\\\\text{Hence (x,y) =(2,-1)}[/tex]
The formula below represents the standard form of a quadratic equation,
ax2 + b + c = 0
Solve for b.
Answer:
[tex]b=-a^2-c[/tex]
Step-by-step explanation:
#3) They say they have 50 total coins together made up of dimes and quarters. They also say that they have $7.25 total. How many quarters do they have?
A. 10
B.15.
C.20.
D.25
Answer:
B: 15 quarters
Step-by-step explanation:
Step 1: Setup Coin Value and Coin Total Equation:
Coin Value Equation → 0.1d + 0.25q = $7.25 where d = dimes and q = quarters
Coin Total Equation → d + q = 50
Step 2: Rearrange Coin Total Equation in terms of dimes (d)
d = 50 - q ← Revised Coin Total Equation
Step 3: Plug in our Revised Coin Total Equation for d into our Coin Value Equation:
0.1(50 - q) + 0.25q = $7.25
0.1(50) - 0.1(q) + 0.25q = $7.25
5 - 0.1q + 0.25q = $7.25
5 + (0.25 - 0.1)q = $7.25
5 + 0.15q = $7.25
Step 4: Subtract 5 from each side of the equation to isolate q
5 - 5 + 0.15q = $7.25 - 5
0.15q = 2.25
Step 5: Divide each side of the equation by 0.15 to isolate q
0.15q
0.15
=
2.25
0.15
q = 15
Step 6: Using our value for q, Solve for d using our Coin Total Equation:
d + 15 = 50
Subtracting 15 from both sides, we get d + 15 - 15 = 50 - 15
d = 35
Summarizing our word problem, we see that 15 quarters and 35 dimes adds up to $7.25
what do i do for the 2 boxes circled in purple? help!
Bidmass working out questions
Answer:
2nd one
Step-by-step explanation:
i think(10+2)^2_4*11=100 in my opinion
what is 70*77 please help
Help a brother out.ill give brainlist
[tex]\text{a. cm}^2\\\\\text{b. cm}^3\\\\\text{c. cm}\\\\\text{d. cm}^2\\\\\text{e. cm}^3\\[/tex]
LAST ATTEMPT IM MARKING AS BRAINLIEST!! (Pythagorean theorem )
Step-by-step explanation:
The Pythagorean theorem is:
[tex] {c}^{2} = {a}^{2} + {b}^{2} [/tex]
where c is the hypotenuse.
The two wires in the sketch are the hypotenuse so we just use the formula
let the wires=x
So:
[tex] {x}^{2} = {12}^{2} + {6}^{2} [/tex]
[tex] {x}^{2} = 144 + 36[/tex]
[tex] {x}^{2} = 180[/tex]
[tex]x = \sqrt{180} [/tex]
[tex]x = 13.42[/tex] feet
Graph the solution to the system
-x+y>2
X+2y>2
Answer:
[tex]\begin{bmatrix}y>2+x\\ y>\frac{2-x}{2}\end{bmatrix}[/tex]
Step-by-step explanation:
Step 1: Solve the system of equations
[tex]\begin{bmatrix}-x+y>2\\ x+2y>2\end{bmatrix}[/tex]
Isolate [tex]y[/tex] for [tex]-x+y>2[/tex]
[tex]\mathrm{Add\:}x\mathrm{\:to\:both\:sides}[/tex]
[tex]-x+y+x>2+x[/tex]
[tex]y>2+x[/tex]
Isolate [tex]y[/tex] for [tex]x+2y>2[/tex]
[tex]\mathrm{Subtract\:}x\mathrm{\:from\:both\:sides}[/tex]
[tex]2y>2-x[/tex]
[tex]\mathrm{Divide\:both\:sides\:by\:}2[/tex]
[tex]\frac{2y}{2}>\frac{2}{2}-\frac{x}{2}[/tex]
[tex]y>\frac{2-x}{2}[/tex]
[tex]\bold{=\begin{bmatrix}y>2+x\\ y>\frac{2-x}{2}\end{bmatrix}}[/tex]
Step 2: Graph
Instructions for graphing:
[tex]\mathrm{1.\:Graph\:each\:inequality\:separately.}[/tex]
[tex]\mathrm{2.\:Choose\:a\:test\:point\:to\:determine\:which\:side\:of\:the\:line\:needs\:to\:be\:shaded.}[/tex]
[tex]3. \mathrm{The\:solution\:to\:the\:system\:will\:be\:the\:area\:where\:the\:shadings\:}\\\mathrm{from\:each\:inequality\:overlap\:one\:another.}[/tex]
When done, it should look like this:
A Quadrilateral ABCD is rotated 55° about point R to create quadrilateral A' B'C'D'. QUICK. PLEASE
Answer:
2.8
Step-by-step explanation:
Answer:
Step-by-step explanation:
2.8 units
Kevin and Randy Muise have a jar containing 80 coins, all of which are either quarters or nickels. The total value of the coins in the jar is $11.80. How many of each type of coin do they have?
Answer:
39 quarters and 41 nickelsStep-by-step explanation:
Let the number of quarters be x and nickels be y.
Given:
Quarter is 25 centsNickel is 5 centsNumber of coins is 80Total amount is $11.80 = 1180 centsWe have equations:
x + y = 8025x + 5y = 1180Solve the system by elimination, subtract 5 times the first equation from the second one:
25x + 5y - 5x - 5y = 1180 - 80*520x = 780x = 780/20x = 39Find the value of y:
39 + y = 80y = 80 - 39y = 41Verify:
25*39 + 5*41 = 975 + 205 = 1180A shirt costing $34 is on sale for 30% off. What is the new price of the shirt after the discount?
Answer:
$23.80
Step-by-step explanation:
30% off means we take 30% off of the original price, or we calculate
(1-30%)=70% of the shirt's price
34*70%=23.8
Points E, D, and H are the midpoints of the sides of ΔTUV. UV=82, TV=106, and HD= 82. Find HE.
Answer:
41
Step-by-step explanation:
53/106 = x/82 similar triangles
x=41
what is 35 divided by 97.3
Answer: 2.78
Step-by-step explanation:
long division
Examine the figure. What is the measure of angle b?
Answer:
b =146
Step-by-step explanation:
34 and b form a straight line so they add to 180
b+34 = 180
b = 180-34
b =146
A Biology test has 20 questions and is worth a total of 100 points. The test
consists of True/False questions worth 2 points each and multiple choice questions
worth 7 points each. How many of the test questions are multiple choice and how
many of the test questions are True/ False?.
# of true/false questions =
# of multiple choice questions
PLEASE HELP ME I WILL GIVE BRAINLY
Answer:
12 multiple choice and 8 True/False
Step-by-step explanation:
To do this we set up a system of equations. Let x represent the True/Fale questions and y represent the multiple-choice questions. Here is a system we can use:
x + y = 20
2x + 7y = 100
We can solve this by using elimination. To do this we multiply one equation by a number, and add them together. If we multiply the first equation by -2, the "x"s will, when added together, cancel out so we can solve for y.
-2(x + y = 20)
-2x - 2y = -40
Now add them together
5y = 60
Solve for y.
y = 12
This means there are 12 multiple choice questions. 20 - 12 is 8 True/False questions.
Hope this helps and have a great day! :D
Answer:
8 True/False and 12 Multiple Choice
Step-by-step explanation:
x+y=20 ...1
2x+7y=100 ...2
Now you can multiply 2 on 1
2x+2y=40
2x+7y=100
Subtract:
-5y=-60
Divide -5 on both sides:
y=12
Substitute y with 12
x+12=20
Subtract 12 on both sides:
x=8
So there are 8 True/False and 12 Multiple Choice
Hope this Helps!
Answer helped by: azailiaskoglund
Simplify 4 to the seventh power over 5 squared all raised to the third power . (4 points)
a
4 to the tenth power over 5 to the fifth power
b
4 to the fourth power over 5
c
4 to the twenty-first power over 5 to the sixth power
d
12 to the seventh power over 15 squared
Answer: The answer is C, 4 to the 21st over 5 to the 6th power.
the cost of a popsicle at the snack stand is $0.75 let p represent the number of popsicles and c represent total cost use an equation to represent the relationship between the numbers of popsicles bought and the total cost
Answer:
0.75p=c
Step-by-step explanation:
Please answer. I will give brainliest to the best answer
Answer:
b
Step-by-step explanation:
took the test a bit ago
3.
Mark is m years old. June is 6 years older that Mark. What is their total
age in 10 years' time?
Answer:
20m+60
Step-by-step explanation:
given,
mark=m
june=m+6(6 years older that mark)
so,
after 10 years,
10(m+(m+6)
=10(2m+6)
=20m+60
Graph all solutions on a number line and provide the corresponding interval notation. 1. 3x + 5>-4 2. 2x+1> -1 3.5-6y < -1 4.7-9y> 43 5.6-a≤6
Graphs attached
Done!
Hopw it helps
What is is b? 2-b/3 =-5/2
Please explain thoroughly
Answer:
I'm not sure you mean 2-(b/3) = -5/2 or (2-b)/3 = -5/2
Step-by-step explanation:
if
2-(b/3) = -5/2
12-2b = -15
12+15 = 2b
27 = 2b
27/2 = b
else
(2-b)/3 = -5/2
2(2-b) = -5×3
4-2b = -15
4+15 = 2b
19 = 2b
19/2 = b
Find an equation of the plane through (-1,4,-3) and perpendicular to the line x-2=t , y+3=t , z=-t
Answer:
x + y -z = 6
Step-by-step explanation:
The equation of the line can be rewritten as ...
(x, y, z) = (2, -3, 0) +t(1, 1, -1)
The direction vector of the line tells you the coefficients of the variables in the equation of the plane. The constant in that plane equation will be the value required to make it pass through the given point.
x + y - z = (-1) +(4) -(-3)
x + y - z = 6 . . . . equation of the plane
There are 11 students in a high school senior class. In how many ways could the yearbook choose the winners of Most Athletic, Class Clown, Best School Spirit, and Best Looking?
The number of ways the yearbook chooses the winners of Most Athletic, Class Clown, Best School Spirit, and Best Looking is 330 ways.
What are permutation and combination?Combination and permutation are two different ways of grouping elements of a set into subsets in mathematics. The elements of the subset can be listed in any order in a combination. The elements of the subset are listed in a specific order in a permutation.
Given that there are 11 students in a high school senior class. The number of ways will be calculated as,
The formula for arrangement,
¹¹C₄ = 11!/(7!)(4!)
¹¹C₄ = 330 ways
To know more about permutation and combination follow
https://brainly.com/question/4658834
#SPJ2
)) The volume of a pyramid with base area B and height his Bh. Jill makes candles
shaped like pyramids to sell at a craft fair. The candles are 6 inches tall and have a base area
of 4 square inches.
1) What is the volume of one of the candles?
1) Write your answer as a whole number or decimal.
cubic inches
Submit
Answer:easy it’s 8
Step-by-step explanation:I just did that same ixl/quiz!
What is the conjugate?
a - square root of a - 1
The conjugate of the expression a - square root of a - 1 is given as follows:
a + square root of a - 1
How to obtain the conjugate of an expression?The conjugate of an expression is obtained for an expression that has two terms.
For the conjugate, we have that:
The signal of the first term is kept.The signal of the second term is inverted.The expression is given as follows:
a - square root of a - 1
The parameters are given as follows:
First term of a.Second term of square root (a - 1).Inverting the - sign to a + sign, the conjugate expression is given as follows:
a + square root of a - 1
More can be learned about the conjugate of a expression at https://brainly.com/question/1584140
#SPJ1
PLEASE HELP WILL MARK BRAINIEST!!!!!!
Answer:
Copy an angle is the best solution with compass and straight edge.
Lucas is having yogurt and an apple for a snack. There are five containers of yogurt in the refrigerator three
are raspberry, one is vanilla, and one is peach. There are also two green apples and three red apples.
If he reaches into the refrigerator to get a yogurt without looking, what is the probability that Lucas wis
choose a raspberry yogurt?
Answer:
His probability of getting a raspberry yogurt is 3/5 or 60%.
Step-by-step explanation:
Pls mark brainliest.
Need help pls answer asap. Sorry the photo quality is bad.
Answer:
Step-by-step explanation:
1 + 3 = 4
so find the point 1/4 of the way from (-1, 2) to (7, 8)
x coordinate
Δx = ¼(7 - (-1)) = 2
x = x₀ + Δx
x = -1 + 2 = 1
y coordinate
Δy = ¼(8 - 2) = 1½
y = y₀ + Δy
y = 2 + 1½ = 3½
(1, 3½)
There are eight swans swimming on a pond and four of those swans are
black. What fraction of the swans are black?
Answer: A. (4/8)
Step-by-step explanation: If there is 4 black swans and 8 swans in total you could see it's 4 black swan out of 8 total swans. You could do
8/8 - 4/8 = 4/8 to find out the answer too.