Question

Alguém pode me ajudar ?

Answer 1

$5^{x-3}+5^{x-2}=30$

$\frac{5^{x-2}}{5}+5^{x-2}=30$

$5^{x-2}\left(\frac{1}{5}+1\right)=30$

$5^{x-2}\cdot\frac{6}{5}=30$

$5^{x-2}=30\cdot\frac{5}{6}$

$5^{x-2}=\frac{30}{6}\cdot5$

$5^{x-2}=5\cdot5$

$5^{x-2}=5^2$

$x-2=2$

$x=4$