How to subtract exponents - SAT Math

Card 0 of 13

Question

If m and n are integers such that m < n < 0 and _m_2 – _n_2 = 7, which of the following can be the value of m + n?

I. –5

II. –7

III. –9

Answer

m and n are both less than zero and thus negative integers, giving us _m_2 and _n_2 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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Question

If , then what is ?

Answer

Follow the order of operations by solving the expression within the parentheses first.

Return to solve the original expression.

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Question

Simplify: 32 * (423 - 421)

Answer

Begin by noting that the group (423 - 421) has a common factor, namely 421. You can treat this like any other constant or variable and factor it out. That would give you: 421(42 - 1). Therefore, we know that:

32 * (423 - 421) = 32 * 421(42 - 1)

Now, 42 - 1 = 16 - 1 = 15 = 5 * 3. Replace that in the original:

32 * 421(42 - 1) = 32 * 421(3 * 5)

Combining multiples withe same base, you get:

33 * 421 * 5

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Question

Solve:

Answer

Subtract the denominator exponent from the numerator's exponent, since they have the same base.

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Question

Answer

To simplify, we can rewrite the numerator using a common exponential base.

Now, we can factor out the numerator.

The eights cancel to give us our final answer.

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Question

Simplify the following expression:

Answer

The correct answer can be found by subtracting exponents that have the same base. Whenever exponents with the same base are divided, you can subtract the exponent of the denominator from the exponent of the numerator as shown below to obtain the final answer:

You do not do anything with the y exponent because it has no identical bases.

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Question

Evaluate

Answer

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

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Question

Evaluate

Answer

Although we have different bases, we know that . As long as exponents are the same, you are allowed to break the base to its prime numbers. Next, we can factor .

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Question

Evaluate

Answer

Although we have different bases, we know that . Therefore our expression is . Remember to apply the power rule of exponents. Next, we can factor out We get .

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Question

Simplify so that all exponents are positive:

Answer

When we divide two polynomials with exponents, we subtract their exponents.

Remember that the question asks that all exponents be positive numbers. Therefore:

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Question

Evaluate:

Answer

When subtracting with exponents, we try to factor out some terms.

We can factor out to get

.

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Question

Evaluate:

Answer

When subtracting with exponents, we try to factor out some terms.

We can factor out to get

.

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Question

Simplify:

Answer

Although we have different bases, we know that .

Therefore,

.

Finally, we factor out to get

.

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