Solve this equation

2^3 * 2^x = 2^(3x)

8*2^x = 2^(3x)           Take log of both sides to get

log8 + xlog2 = 3x log2  divide by log2

log8/log2 + x = 3x

log8/log2 = 2x

1/2 log8/log2 = x = 1.5

$\begin{array}{rcll}2^3 \times 2^x &=& 2^{3x}\\ 2^{3+x}&=&2^{3x}\\ 3+x&=&3x\\ 3&=&2x\\ 1.5 &=&x \end{array}$