## Algebra 1

$1$
Given expression : $(mg^{4})^{-1}(mg^{4})$ Now, $a^{-1}=\frac{1}{a}$ Hence, $(mg^{4})^{-1}=\frac{1}{mg^{4}}$ Thus, the expression becomes : $\frac{1}{mg^{4}}$ X $mg^{4}$ = $1$