# How do you simplify b^4*b^-4 and write it using only positive exponents?

$1$
Using the $\textcolor{b l u e}{\text{laws of exponents}}$
color(orange)"Reminder " color(red)(bar(ul(|color(white)(2/2)color(black)(a^mxxa^n=a^(m+n)" and " a^0=1)color(white)(2/2)|)))
$\Rightarrow {b}^{4} \times {b}^{-} 4 = {b}^{4 + \left(- 4\right)} = {b}^{0} = 1$