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2 years ago

Which of the following could be the value of x in the equation x^2 - 21 = 100 Choose all the correct answers

Mathematics

1 answer:

konstantin123 [22]2 years ago

4 0

How to solve your problem

x^{2}-21=100

Quadratic formula

Factor

Move terms to the left side

x^{2}-21=100

x^{2}-21-100=0

Subtract the numbers

x^{2}\textcolor{#C58AF9}{-21}\textcolor{#C58AF9}{-100}=0

x^{2}\textcolor{#C58AF9}{-121}=0

Use the quadratic formula

x=\frac{-\textcolor{#F28B82}{b}\pm \sqrt{\textcolor{#F28B82}{b}^{2}-4\textcolor{#C58AF9}{a}\textcolor{#8AB4F8}{c}}}{2\textcolor{#C58AF9}{a}}

Once in standard form, identify a, b, and c from the original equation and plug them into the quadratic formula.

x^{2}-121=0

a=\textcolor{#C58AF9}{1}

b=\textcolor{#F28B82}{0}

c=\textcolor{#8AB4F8}{-121}

x=\frac{-\textcolor{#F28B82}{0}\pm \sqrt{\textcolor{#F28B82}{0}^{2}-4\cdot \textcolor{#C58AF9}{1}(\textcolor{#8AB4F8}{-121})}}{2\cdot \textcolor{#C58AF9}{1}}

Simplify

Evaluate the exponent

Multiply the numbers

Add the numbers

Evaluate the square root

Add zero

Multiply the numbers

x=\frac{\pm 22}{2}

Separate the equations

To solve for the unknown variable, separate into two equations: one with a plus and the other with a minus.

x=\frac{22}{2}

x=\frac{-22}{2}

Solve

Rearrange and isolate the variable to find each solution

x=11

x=-11

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If you draw a tree to show the number of ways to spin a spinner with three regions twice, how many possibilitdies would there be

LenaWriter [7]

Answer: There would be 9 possibilities.

Step-by-step explanation:

Given : The number of regions in the spinner = 3

if we spin the spinner twice, then by using fundamental principal of counting , the number of possibilities is given by :-

$3\times3=9$

Therefore, there would be 9 possibilities.

The Fundamental Counting Principle is a method to calculate the number of possibilities by multiplying the events together to get the total number of possibilities.

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3 years ago

In psychology lab, Tetiana is conducting an experiment on depth perception using the Howard-Dolman box. Inside the box are two v

erma4kov [3.2K]

Answer:

within-groups

Step-by-step explanation:

According to my research on the scientific method, I can say that based on the information provided within the question the independent variable is being manipulated within groups, because she is not using a pretest and her design is within-groups. This is because she is using the posttest-only control group design which is a research design where at least two groups, one of which does not receive a treatment or intervention, and data is collected on the outcome measure after the treatment or intervention.

I hope this answered your question. If you have any more questions feel free to ask away at Brainly.

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3 years ago

Does each function describe exponential growth or decay?

Aleksandr [31]

<h3>Answer: Only first two are exponential growth function and last three functions are exponential decay functions.</h3>

Step-by-step explanation: We need to describe exponential growth or decay for the given functions.

The standard exponential function equation is

$y=a(b)^x$ .

Where a is the initial value and b is the growth factor.

Note: If value of b > 1, it would be an exponential growth and if b < 1, it would be an exponential decay.

Let us check them one by one.

$y=(1.008^{1/12}})^{12t}$ => $y=(1.008^})^{1/12\times{12t} }$

=> $y= (1.008)^t$ .

Value of b is 1.008 > 1, therefor it's an exponential growth function.

y=250(1+0.004)^t, also have b>1 therefor it's an exponential growth function.

All other functions has b values less than 1, therefore only first two are exponential growth function and last three functions are exponential decay functions.

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3 years ago

Write an expression for twelve divided by a number

Rom4ik [11]

12 ÷ 3= 4. Hope this helps. ;)

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3 years ago

(06.01) What is the value of the expression shown below? 3 over 6 to the power of 2 + 7 × 4 − 5 6 and 1 over 4 6 and 1 over 2 23

never [62]

Answer: 23(1/4)

Step-by-step explanation: this is the answer you can star resolving the equation into the parenthesis

(3/6)² + 7 *4 - 5

if we elevate to the power of 2 the values into the parenthesis, we get the following equation.

(9/36) + 7*4 -5

after this we follow with the values into the parenthesis, if you divide 9 over 36 we get the following result

9/36 = 0.25

then we get the following equation

0.25 +7*4 - 5

after that we can resolve the multiplication getting the following equation

0.25 +28 - 5

then if we resolve the subtraction, we will get this result.

28-5 = 23

then we have 0.25 + 23 this equation is equal to 23.25

if you follow the answer will be one with 23, then we get the possible results, if you divide 1/4=0.25

then we get that the result is

23(1/4)

8 0

3 years ago

Read 2 more answers