Question 420792
We can write {{{8^(x+5)}}} as {{{(2^3)^(x+5)}}} --> {{{2^(3x+15)}}}. Also, {{{4^x = (2^2)^x = 2^(2x)}}}. Hence,


{{{2^(3x+15) = 2^(2x)}}} The exponents must be equal (we can take the logarithm of both sides)


{{{3x+15 = 2x}}} --> {{{x = -15}}}.