Log16 (42) * log7 (8) - 3log49 корень из 6

Log16 (42) = log7 (42) / log7 (16) = (log7 (7) + log7 (6)) / log7 (2^4) = (1+log7 (6)) / 4log7 (2)

log7 (8) = log7 (2^3) = 3log7 (2)

Log16 (42) * log7 (8) = (1+log7 (6)) / 4log7 (2) * 3log7 (2) = 3/4 (1+log7 (6)) = 3/4+3/4*log7 (6)

3log49 (√6) = 3*log7 (6^ (1/2)) / log7 (49) = 3*1/2*log7 (6) / 2=3/4*log7 (6)

3/4+3/4*log7 (6) - 3/4*log7 (6) = 3/4

Ответ: 3/4