If m^(-1) = -1/3, then m^(-2) is equal to
A) -9
B) -3
C) -1/9
D) 1/9
E) 9
OA: D
If m^(-1) = -1/3 (OG16)
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m^(-1) = 1/mboomgoesthegmat wrote:If m^(-1) = -1/3, then m^(-2) is equal to
A) -9
B) -3
C) -1/9
D) 1/9
E) 9
OA: D
We're told that m^(-1) = -1/3
This means that 1/m = -1/3
So, we know that m = -3
This means that m^(-2) = (-3)^(-2)
= 1/9
= D
RELATED RESOURCE (video):
Negative exponents: https://www.gmatprepnow.com/module/gmat ... video/1028
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Another solution:boomgoesthegmat wrote:If m^(-1) = -1/3, then m^(-2) is equal to
A) -9
B) -3
C) -1/9
D) 1/9
E) 9
OA: D
Given: m^(-1) = -1/3
Square both sides to get: [m^(-1)]^2 = (-1/3)^2
Simplify: m^(-2) = (-1/3)(-1/3)
So, m^(-2) = 1/9
Answer: D
RELATED RESOURCE (video)
- Laws of exponents - part I: https://www.gmatprepnow.com/module/gmat ... video/1025
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Notice that m^(-2) = [m^(-1)]^2, therefore,boomgoesthegmat wrote:If m^(-1) = -1/3, then m^(-2) is equal to
A) -9
B) -3
C) -1/9
D) 1/9
E) 9
m^(-2) = (-1/3)^2 = 1/9
Alternate Solution:
We re-express m^(-1) as 1/m. We are given that m^(-1) = -1/3, so we see that m = -3.
To evaluate m^(-2), we substitute -3 for m, yielding (-3)^(-2) = 1/(-3)^2 = 1/9.
Answer: D
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