How to subtract exponents - PSAT Math
Card 0 of 4
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
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
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.
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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If 
, then what is 
?
If
Follow the order of operations by solving the expression within the parentheses first.
Return to solve the original expression.
Follow the order of operations by solving the expression within the parentheses first.
Return to solve the original expression.
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Solve:
Solve:
Subtract the denominator exponent from the numerator's exponent, since they have the same base.
Subtract the denominator exponent from the numerator's exponent, since they have the same base.
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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.
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.
Compare your answer with the correct one above