Given the equation log2x + log2(x – 7) = 3, solve for x.

Answers

Answer 1

Answer:

         x∈{-1, 8}

Step-by-step explanation:

[tex]\log_2x +\log_2(x-7) = 3\\\\\log_2[x\cdot(x-7)]= 3\log_22\\\\\log_2(x^2-7x)= \log_22^3\\\\x^2-7x=2^3\\\\x^2-7x-8=0\quad\implies \quad a=1\,,\ \ b=-7\,,\ \ c=-8 \\\\x=\dfrac{-(-7)\pm\sqrt{(-7)^2-4\cdot1\cdot(-8)}}{2\cdot1}= \dfrac{7\pm\sqrt{49+32}}{2} =\dfrac{7\pm\sqrt{81}}{2}\\\\x=\dfrac{7+9}2=8\qquad\vee\qquad x=\dfrac{7-9}2=-1[/tex]


Related Questions

which value of x is the solution set of 2(3x-1)≥4x-6

Answers

Answer:

-1

General Formulas and Concepts:

Pre-Algebra

Order of Operations: BPEMDAS

Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to Right

Equality Properties

Multiplication Property of Equality Division Property of Equality Addition Property of Equality Subtract Property of Equality

Step-by-step explanation:

Step 1: Define

2(3x - 1) ≥ 4x - 6

Step 2: Solve for x

Distribute 2:                                 6x - 2 ≥ 4x - 6Subtract 4x on both sides:          2x - 2 ≥ -6Add 2 on both sides:                   2x ≥ -4Divide 2 on both sides:               x ≥ -2

Here we see that any value x greater than or equal to -2 would work as a solution.

Given the two angles:

1) two angles are:
Congruent
Supplementary
Complementary

2) because they are...
Corresponding
Consecutive interior
Alternate exterior
Alternate interior

Answers

Answer:

congruent, alternate exterior

Step-by-step explanation:

For the first question, the angles are congruent (they are not complementary because they dont add p to 90 degrees, and they are not supplementary because they dont add up to 180 degrees so they must be congrunet)

For the second- they are alternate exterior (i know that they are on the outisde so they are exterior)

n/-5 = 7
What is n

Please answer with an explanation of how you completed the equation

Answers

Answer: n= -35

Step-by-step explanation: N= 7(-5) =-35

4+8 890-5+764+88=765678987654

Answers

Answer:

no its 1749

Step-by-step explanation:

PLZ I NEED HELP!!A tree is 12 feet tall and casts a shadow 9 feet long. A building nearby casts a shadow that measures 24 feet. How tall is the building?
A. 24
B. 21
C. 27
D. 32

Answers

Answer:

D. 32 feet

Step-by-step explanation:

A tree is 12 feet tall and casts a 9-foot shadow.

The shadow is 3/4 the length of the tree (9/12 = 3/4).

We know the shadow of a nearby building is 24 feet long.

That would be 3/4 of the height of the building.

So, fidn the reciprocal of 3/4 (4/3) and multiply by 24.

24/1 * 4/3

Cross-cancellation

8/1 * 4/1

8 * 4

The building is 32 feet tall, which is D.

help plz plz plz plz

Answers

Step-by-step explanation:

2(4y-44)°+2(3y+35)°=360°

(8y-88)°+(6y+70)°=360°

(8y+6y+70-88)°=360°

(14y-12)°=360°

14y=360°+12°

14y=372°

y=372°/14

y=27°

acute angle

(4y-44)° =4(27)°-44°

=108°-44°=64°

Which method will NOT get you to the point (4,3.5)?
A. Starting at the origin, go 3.5 spaces to the right and then 4 spaces up.
B. Starting at the origin, go 3.5 spaces up and then 4 spaces to the right.
C. Starting at the origin, go 4 spaces to the right and then 3.5 spaces up.
D. Put one finger on 4 on the x-axis, and put another finger halfway between 3 and 4 on the y-axis. Move the first finger up and the second finger to the right until they meet.

Answers

Answer:

A. Starting at the origin, go 3.5 spaces to the right and then 4 spaces up.

Step-by-step explanation:

if you were to plot this then the point would be (3.5,4) instead of (4,3.5)

Starting at the origin, go 3.5 spaces to the right and then 4 spaces up will not get you to the point (4,3.5) but will get you (3.5, 4). The correct option is A.

What are coordinates?

Coordinates are a pair of integers (Cartesian coordinates), or occasionally a letter and a number, that identify a certain place on a grid, often referred to as a coordinate plane.

We have the point (4, 3.5).

And let the point (x, y).

By comparing,

we get,

x = 4 and y = 3.5

That means, the value in the x coordinate is 4 and y coordinate is 3.5.

As the signed distance from the origin in the direction along the x-axis, the first value x is known as the x-coordinate (or x-component). The x-coordinate indicates the distance from the y-axis to the right (if x is positive) or left (if x is negative).

Additionally, the y-coordinate indicates how many steps are needed to up either positively or negatively on the y-axis.

So, the point is 4 point right from the origin and 3.5 point up from the origin.

Therefore, starting at the origin, go 3.5 spaces to the right and then 4 spaces up will not get you to the point (4,3.5)

To learn more about the coordinates;

https://brainly.com/question/27749090

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Solve the following multi-step equation: 4(2 - 4x) - 3x = 65

Answers

Answer:

x = -3

Step-by-step explanation:

4(2 - 4x) - 3x = 65

Distribute the 4.

8 - 16x - 3x = 65

Combine like terms.

8 - 19x = 65

-19x = 57

Divide by -19 to isolate x.

x = 57/-19

x = -3

Check.

4(2 - 4(-3)) - 3(-3) = 65

4(2 - (-12) + 9 = 65

4(14) + 9 = 65

56 + 9 = 65

65 = 65

The solution of the given linear equation 4(2 - 4x) - 3x = 65 is  -3.

Two algebraic expressions separated by an equal symbol in between them and with the same value of the expression are called equations.

Example = 2x +4 = 12

here, 4 and 12 are constants and x is variable.

The solution of the equation 4(2 - 4x) - 3x = 65 is calculated as:

4(2 - 4x) - 3x = 65

Multiply the expressions inside the brackets,

8 - 16x -3x = 65

8 - 19x = 65

Subtract 8 from both the sides,

-19x = 65- 8

-19x = 53

Divide both side by -19

[tex]x = \dfrac{-53}{19}[/tex]

Thus, the value of x is -3.

Learn more about equations here:

https://brainly.com/question/14686792

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You want to limit the amount of television you watch to an average of at most 2 hours a week during and eight week period. How many hours x can you watch in the eight weeks to meet your goal.

Answers

Answer:

x = 16hours

Step-by-step explanation:

Given

Total number of hours to watch the television a week is 2 hours, that is;

2hours =1 week

We are to find the number of hours to watch in eight weeks to meet the goal

x hours = 8 weeks

Divide both expressions;

2/x = 1/8

Cross multiply

1 * x = 2*8

x = 16

Hence he will use 16hours to watch the television in 8 weeks

Omgggg please please please help me I really really really need help on this. Please can you guys help me solve this problem?

Answers

Answer:

The volume of the figure is: 60840[tex]\pi ^3[/tex], or approximately about 191037.6 ft^3.

Step-by-step explanation:

This 3D figure can be split into two separate figures, a half-sphere, and a cone.

Let's first try to find the volume of the half-sphere.

The formula for the volume of the half-sphere is [tex]\frac{2}{3}\pi r^3[/tex], so substituting 39 for r gives us a volume of 39546[tex]\pi \\\\[/tex]ft^3, or about 124174.44 ft^3.

Next, let's find the volume of the cone. We see that the radius of the cone is once again 39 ft, and the height of the cone i s just 81-39, or 42 ft.

The volume of a cone is [tex](\pi r^2h)/3[/tex], and substituting 39 for r and 42 for h, we obtain a result of 21294[tex]\pi^3[/tex], or about 66863.16

Thus, the final volume of the figure is: 60840[tex]\pi ^3[/tex], or approximately about 191037.6 ft^3

click to see the problem

Answers

Answer:

C is your correct answer i think

Step-by-step explanation:

I think the answer would be C

Lin is reading a 47-page book. She read the first 20 pages in 35 minutes. Rounding to the nearest minute, how long will it take Lin to finish the entire book?

Answers

Answer: 82.25 minutes

Step-by-step explanation:

First convert the minutes she took to hours. This would be:

= 35/60

She is reading at a speed of 20 pages per 35/60 hours.

To finish 47 pages therefore, she will take:

= (47 * 35/60) / 20

= 1.37083 hours

Converted to minutes that would be:

= 1.37083 * 60 mins

= 82.25 minutes

are you a robot cause i think you are

Answers

No I am not a robot what u mean
i am not. I’m actually an alien i come from planet Kepler-452b. Don’t know if the world knows my planet yet. They were supposed to find out in 2020 when i arrived

What is the factored form of n2 - 25?
?
(n-25)(n-1)
(n - 5)(n + 5)
(n + 5)(n + 5)
LO (n - 25)n + 1)

Answers

Answer:

(n-5)(n+5)

Step-by-step explanation:

n^2-25

(n-5)(n+5)

In his last basketball game, Chris attempted a total of 25 shots and made 18 of them.What is the ratio of how many shots missed and how many shots made?

Answers

Answer:

7:18

Step-by-step explanation:

Chris attempted a total of 25 shots

He made 18 shots

Number of shots missed= 25-18

= 7

Therefore the ratio of shots missed and shots made can be calculated as follows

7:18

Hence the ratio is 7:18

How many should I have?

Answers

Answer:

You should have 95 bananas.

Step-by-step explanation:

multiply 19 by 5.

Answer:

95 bananas ..I'm here for the points

a company sets up a food booth at the county fair. the fee for the food booth is 100$ plus 5$ per day. which expression can be used to determine how much money it would cost after x days?

Answers

Answer:

Total cost after x days = 100 + 5(x)

Step-by-step explanation:

Given:

Fixed cost = $100

Per day charges = $5

Find:

Total cost after x days

Computation:

Assume;

Number of days = x

Total cost after x days = $100 + $5(x)

Total cost after x days = 100 + 5(x)

WILL MARK BRAINLIEST!! This goes to a part 2 of my last post. Sketch a new graph of this relationship.​

Answers

What can I find the part 2

Which is a graph of the solution of the inequality -5m+10>70

Answers

Answer:

solving form; m< -12  

Step-by-step explanation:

On a linear graph there would be an open circle on the number -12 and the line would be pointing left

...............°__________°.................​

Answers

Answer:

35

Step-by-step explanation:

i pretty sure

Hey again!

The answer to your question is 122.5 feet²

We can find the dimensions of the new figure:

2 x 3.5 = 7

5 x 3.5 = 17.5

Area = length x width, so 7 x 17.5 = 122.5

Hope it helps!

help please!!!!!!!!!!!!!!!!!!!!!!!

Answers

9514 1404 393

Answer:

  a) $336

  b) $1036

Step-by-step explanation:

a) The interest is computed using the formula ...

  I = Prt

where P is the amount invested at rate r for t years.

  I = $700·0.08·6 = $336

The interest earned is $336.

__

b) The balance of the account is the sum of the original amount and the interest earned:

  balance = $700 +336 = $1036

The balance of the account is $1036.

what is the measure of the central angle that represents blue backpacks?

Answers

Answer:

Yes it is 10

Step-by-step explanation:

What is the answer of this q ❓​

Answers

Answer:

68

Step-by-step explanation:

lets mijdkdefbdhnrr

help plz plz plz plz will mark brainliest

Answers

Answer:

x = 68°

Step-by-step explanation:

Let us solve the question

In the given figure

∵ The ray WD bisects ∠ZWN

→ That means it divides the angle into two equal angles, ∠ZWD and ∠DWN

m∠ZWD = m∠DWN

∵ m∠ZWD = 5v - 7

∵ m∠DWN = 4v + 8

→ Equate the measures of the two angles

5v - 7 = 4v + 8

→ Add 7 to both sides

∵ 5v - 7 + 7 = 4v + 8 + 7

5v = 4v + 15

→ Subtract 4v from both sides

∵ 5v - 4v = 4v - 4v + 15

v = 15

∵ x = m∠ZWD

x = 5v - 7

→ Substitute v by 15

∵ x = 5(15) - 7

∴ x = 75 - 7

x = 68°

CAN SOMEONE PLEASE HELP ME I WLL MARK BRAINLIEST!!!

Answers

Answer:

1/2 inch: 3 feet

Step-by-step explanation:

It says in the bottom right corner.

Answer:2tt

Step-by-step explanation:

huh

Select "equivalent" or "not equivalent" for each pair of expressions.
Expressions
equivalent or not equivalent?
5x - 7+ 3x and 3x – 7+ 5x equivalent not equivalent
4y + 9 + 3y and 3y+9+ 4y equivalent not equivalent
62 - 2x + 4 and 4 + 2z. - 62 equivalent not equivalent

Answers

Answer:

Step-by-step explanation:

1. Not

2. Yes

3. not

Find the equation of the line through the points (-2,-9) and (5,12)
y =

Answers

Answer:

y - 12 = 3(x - 5)

Step-by-step explanation:

Going from (-2, -9) to (5, 12), x (the run) increases by 7 and y (the rise) increases by 21.  Thus, the slope of this line is m = rise / run = 21/7 = 3.

Using the point-slope formula y - k = m(x - h), we get:

y - 12 = 3(x - 5)

Are x+x^2 and u+u^2 the same function? If x and u are for all real numbers? A- these are the same function B- If x and u are two different numbers, the functions are different C- there is not enough information to answer this question.

Answers

Answer:

(a) These are the same function

Step-by-step explanation:

Given

[tex]x + x^2[/tex] and [tex]u + u^2[/tex]

Required

Are they the same?

Yes, they are the same function and this is proved below.

[tex]x + x^2[/tex]

Represent as a function:

[tex]f(x) = x + x^2[/tex]

[tex]u + u^2[/tex]

Represent as a function

[tex]f(u) = u + u^2[/tex]

Let x = u

Substitute u for x in [tex]f(x) = x + x^2[/tex]

[tex]f(u) = u + u^2[/tex]

This implies that:

[tex]f(x) = f(u)[/tex]

[tex]x + x^2 =u + u^2[/tex]

PS: The information that x and u are real numbers are for all real numbers; So, we can not assume that x and u are different numbers

Hence:

(b) and (c) are wrong

list the integers within the interval
[tex] 8 \leqslant x < 16[/tex]


Answers

8,9,10,11,12,13,14,15

do not include 16 as it is not equal to (the line underneath the ‘crocodile’ whereas the ‘crocodile’ next to 8 has a line therefore it is equal to and so you include it.

Which property is demonstrated by the equation (5 + a) + 3 = (a + 5) + 3?

Answers

Answer:

Communitive Property

Step-by-step explanation:

Commutative property = 2 + 3 = 3 + 2 or 2(3) = 3(2)

Associative Property = (2 x 3) 5 = 2 (3 x 5) or (2 + 3) + 5 = 2 + (3 + 5)

Inverse Property = 2 + (-2) = 0 or (2/1)(½) = 1

Basic Definitions:

Commutative Property - Gives you the ability to switch the order of the numbers in an expression.

Associative Property - Let's you move the parenthesis in an expression but not the numbers.

Inverse - Uses numbers like 0 and 1.

Using these basic definitions and examples, we can summarize that the best answer would be Communitive Property

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