Question

3 elevado a x+1 + 3 elevado a x+2 = 12

Answer 1

$3 ^{x+1} + 3^{x+2} =12$

$3 ^{x+1} + 3^{x+2} = 3 +9$
$3 ^{x+1} + 3^{x+2} = 3^{1} + 3^{2}$

x+1 + x+2  = 1+2
2x+3 =3
2x=0
x=0

Espero ter Ajudado >.<