# How do you solve 10^(-x+4) +7 = 5  and find any extraneous solutions?

For $a > 0 , {a}^{n} > 0 \mathmr{and} \lim n \to - \infty$ of ${a}^{n} = 0$.
So, ${10}^{- x + 4} > 0$. Here, it is valued as $- 2$.