SAT Math : Exponents

Study concepts, example questions & explanations for SAT Math

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Example Questions

Example Question #21 : How To Add Exponents

Evaluate 

Possible Answers:

Correct answer:

Explanation:

When adding exponents, we don't multiply the exponents but we try to factor to see if we simplify the addition problem. In this case, we can simplify it by factoring . We get .

Example Question #91 : Exponents

Evaluate 

Possible Answers:

Correct answer:

Explanation:

When adding exponents, we don't multiply the exponents but we try to factor to see if we simplify the addition problem. In this case, we can simplify it by factoring . We get .

Example Question #23 : How To Add Exponents

Evaluate 

Possible Answers:

Correct answer:

Explanation:

Although we have different bases, we do know . Therefore our expression is . Remember to apply the power rule of exponents. Then, now we can factor 

Example Question #23 : How To Add Exponents

If \dpi{100} \small r and \dpi{100} \small s are positive integers, and \dpi{100} \small 25\left ( 5^{r} \right )=5^{s-2}, then what is \dpi{100} \small s in terms of \dpi{100} \small r?

Possible Answers:

\dpi{100} \small r+4

\dpi{100} \small r+1

\dpi{100} \small r

\dpi{100} \small r+2

\dpi{100} \small r+3

Correct answer:

\dpi{100} \small r+4

Explanation:

\dpi{100} \small 25\left ( 5^{r} \right ) is equal to  which is equal to \dpi{100} \small \left ( 5^{r+2} \right ). If we compare this to the original equation we get \dpi{100} \small r+2=s-2\rightarrow s=r+4

Example Question #25 : How To Add Exponents

Evaluate:

Possible Answers:

Correct answer:

Explanation:

When adding exponents, you want to factor out to make solving the question easier.

 we can factor out  to get 

.

We have the same base so we just apply the exponent rule for multiplication to get 

.

Example Question #26 : How To Add Exponents

Which of the following is equivalent to ?

Possible Answers:

Correct answer:

Explanation:

Although each base is different, we can convert them to a common base of  

We know 

,

and 

.

Remember to apply the power rule of exponents.

Therefore we have 

.

We can factor out  to get 

.

Example Question #27 : How To Add Exponents

Simplify: 

 

Possible Answers:

Correct answer:

Explanation:

When adding exponents, you want to factor out to make solving the question easier.

 

We can factor out  to get 

.

Now we can add exponents and therefore our answer is 

.

Example Question #92 : Exponents

Given  , what is the value of ?

Possible Answers:

3

5

7

11

9

Correct answer:

7

Explanation:

Express  as a power of ; that is: .

Then .

Using the properties of exponents, .

Therefore, , so .

Example Question #93 : Exponents

If , what is the value of ?

Possible Answers:

Correct answer:

Explanation:

Since we have two ’s in  we will need to combine the two terms.

For  this can be rewritten as

So we have .

Or 

Divide this by

Thus  or 

*Hint: If you are really unsure, you could have plugged in the numbers and found that the first choice worked in the equation.

Example Question #13 : Exponents

If m and n are integers such that m < n < 0 and m2 – n2 = 7, which of the following can be the value of m + n?

            I. –5

           II. –7

          III. –9

Possible Answers:

II and III only

II only

I, II and III only

I only

I and II only

Correct answer:

II only

Explanation:

m and n are both less than zero and thus negative integers, giving us m2 and n2 as perfect squares. The only perfect squares with a difference of 7 is 16 – 9, therefore m = –4 and n = –3.

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