Answer
$x=1$
Work Step by Step
RECALL:
(1) $a^m \cdot a^n = a^{m+n}$
(2) If $a^m=a^n$, then $m=n$
Use rule (1) above to obtain:
$3^{x+2+x}=81
\\3^{2x+2}=81$
Note that $81=3^4$.
Write $81$ as $3^4$ to obtain:
$3^{2x+2} = 3^4$
Use rule (2) above to obtain:
$2x+2=4$
Subtract $2$ on both sides of the equation to obtain:
$2x = 2$
Divide $2$ on both sides of the equation to obtain:
$x=1$
