Log 1 7 7 x 2. Log2 x 2 log2 x2+х-7. log2(7-x)=5. log7(2x+5)=2. log_7⁡〖(х-2)〗 + log_7⁡〖(х+2)〗 = log_7⁡〖(2х-1)〗.