ACT Math : How to add exponents

Study concepts, example questions & explanations for ACT Math

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Example Questions

Example Question #5 : Exponential Operations

If , what is the value of ?

Possible Answers:

Correct answer:

Explanation:

Rewrite the term on the left as a product. Remember that negative exponents shift their position in a fraction (denominator to numerator).

The term on the right can be rewritten, as 27 is equal to 3 to the third power.

Exponent rules dictate that multiplying terms allows us to add their exponents, while one term raised to another allows us to multiply exponents.

We now know that the exponents must be equal, and can solve for .

 

Example Question #11 : How To Add Exponents

If , what is the value of ?

Possible Answers:

Correct answer:

Explanation:

Since the base is 5 for each term, we can say 2 + n =12.  Solve the equation for n by subtracting 2 from both sides to get n = 10.

Example Question #2233 : Act Math

Which expression is equivalent to the following?

Possible Answers:

None of these

Correct answer:

None of these

Explanation:

The rule for adding exponents is . We can thus see that  and  are no more compatible for addition than  and  are.

You could combine the first two terms into , but note that PEMDAS prevents us from equating this to  (the exponent must solve before the distribution).

Example Question #2234 : Act Math

Express as a power of 2: 

Possible Answers:

The expression cannot be rephrased as a power of 2.

Correct answer:

Explanation:

Since the problem requires us to finish in a power of 2, it's easiest to begin by reducing all terms to powers of 2. Fortunately, we do not need to use logarithms to do so here.

Thus, 

Example Question #42 : Exponents

Simplify the following expression:

Possible Answers:

Correct answer:

Explanation:

When multiplying bases that have exponents, simply add the exponents. Note that you can only add the exponents if the bases are the same. Thus:

 

Example Question #51 : Exponents

Simplify the following:

Possible Answers:

Correct answer:

Explanation:

When multiplying two exponential expressions with the same bases, add the exponents. In this problem, the answer turns out to be .

Example Question #2241 : Act Math

Simplify the following

.

Possible Answers:

 

Correct answer:

 

Explanation:

Begin by performing the last group's multiplication:

Now, remember that you treat variables and their powers as similar terms to be combined. Therefore, you can combine the  and  terms, giving you:

 

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