Question

7 · 3^x-2 - 2 · 3^x-1 + 5 · 3^x-3 = 24

Answer 1

$7cdot 3^{x-2}-2cdot 3^{x-1}+5cdot 3^{x-3}=24\ 3^{x-3}(7cdot 3-2cdot 3^2+5)=24\ \ 8cdot3^{x-3}=24,,, |:8\ \ 3^{x-3}=3\ \ x-3=1\ \ x=4$