Логарифмы)))))))))))))))))
(log6(2) +log6(3) + (2^log2(4)))^log5(7) = (log6(2) +log6(3) + 4 )^log5(7)= (log6(2*3) + 4 )^log5(7)= (1 + 4 )^log5(7)= 5^log5(7)=7