Question

5 raised to power x-3 ×3 raised to power 2x-8=225

Answer 1

$225=3*3*5*5=3^{2}*5^{2}$
$5^{x-3} * 3^{2x-8} = 5^{2} * 3^{2}$
comparing the powers,
x-3=2
thus x=5

2x-8=2
2x=10
x=5

hope this helps!

the question you asked later:-
5 raised to power x-5 upon 3 raised to power-2(x-5)=1.
$\frac{ 5^{x-5} }{ 3^{-2(x-5)} } =1$
negative power means we have to shift it's place from denominator to numerator so we get,
$5^{x-5} * 3^{2(x-5)} =1= 3^{0} * 5^{0}$
now compare the powers,
x-5=0
x=5 &
2(x-5)=0
x-5=0
x=5