Решение
(log5 12 - 2log5 2)/(log5 18 + log5 0,5) = (log5 12/4) / (log5 18*0,5) =
= log5 3 / log5 9 = log5 3 / 2log5 3 = 1/2
2) (3lg 4 + lg 0,5) / (lg 7 - lg 14) = (lg 64*0,5) / (lg 7/14) =
= lg 32 / lg (1/2) = lg (2^5) / lg (2^(-1)) = 5 lg 2 / - lg 2= - 5