Question

What is the value of x in this simplified expression? (-j)^-7=1/(-j)^x

Answer 1

$x=7\\\\\text{because}\\\\a^{-n}=\dfrac{1}{a^n};\ a\neq0\\\\(-j)^{-7}=\dfrac{1}{(-j)^7}$

$\text{Minus in a power means inverse.}$

$a^{-1}=\dfrac{1}{a}\\\\(-j)^{-7}=(-j)^{7\cdot(-1)}=\left[(-j)^7\right]^{-1}=\dfrac{1}{(-j)^7}\\\\\text{Used:}\\\\(a^n)^m=a^{n\cdot m}$