Problem: (4−1−3−1)−1=\left(4^{-1}-3^{-1}\right)^{-1}=(4−1−3−1)−1=
Answer Choices:
A. −12-12−12
B. −1-1−1
C. 112\dfrac{1}{12}121
D. 111
E. 121212
Solution:
(4−1−3−1)−1⇌(14−13)−1=(−112)−1=−12\left(4^{-1}-3^{-1}\right)^{-1} \rightleftharpoons\left(\dfrac{1}{4}-\dfrac{1}{3}\right)^{-1}=\left(-\dfrac{1}{12}\right)^{-1}=-12(4−1−3−1)−1⇌(41−31)−1=(−121)−1=−12.