log2x+2log4x+3log8x+4log16x=4

log_2 x+ 2*\frac{1}{2} log_2 x+3* \frac{1}{3} log_2 x+4* \frac{1}{4} log_2 x=4 \\ 4log_2 x=4 \\ log_2 x=1 \\ x=2