# How do you evaluate the expression for 2^x if x=-2 and if x=3?

Jan 6, 2017

For each of these you substitute the value for $x$ in the expression.

Problem 1: Solve for x = −2

${2}^{-} 2$

We can use this rule for exponents to rewrite this problem:

${x}^{\textcolor{red}{a}} = \frac{1}{x} ^ \textcolor{red}{- a}$

${2}^{\textcolor{red}{- 2}}$

$\frac{1}{2} ^ \textcolor{red}{- - 2}$

$\frac{1}{2} ^ \textcolor{red}{2}$

$\frac{1}{4}$

Problem 1: Solve for $x = 3$

${2}^{3}$

$2 \times 2 \times 2$

$8$