Question

I need help please !!!!

Answer 1

$8^{b-1}=2^{4b+4}\\\\\left(2^3\right)^{b-1}=2^{4b+4}\\\\2^{3(b-1)}=2^{4b+4}\iff3(b-1)=4b+4\\\\3b-3=4b+4\ \ \ |+3\\\\3b=4b+7\ \ \ |-4b\\\\-b=7\to \boxed{b=-7}$

$\text{check:}\\\\L_s=8^{-7-1}=8^{-8}=(2^3)^{-8}=2^{3\cdot(-8)}=2^{-24}\\\\R_s=2^{4\cdot(-7)+4}=2^{-28+4}=2^{-24}\\\\L_s=R_s\ \ \ \text{CORRECT :)}$

$\text{Used:}\\(a^n)^m=a^{n\cdot m}$