F.4 log

log8x^2/log2x
=log[2*(2x)^2]/log2x
=(log2+2log2x)/log2x
=log2/log2x + 2

I assume the numbers 8 and 2 are the base of logarithm??
log_8 x^2 / log_2 x
= (logx^2 / log8) / (logx / log2)
= (2log x / 3log2) / (logx / log2)
= 2/3