Упростите выражение2/7*(1.4a-3 целых1/2b)-1.2*(5/6a-0.5b)
2/7 * (1,4a - 3 1/2b) - 1.2 * (5/6a - 0.5b) = 2/7 * (14/10a -7/2b) - 12/10 * (5/6a - 1/2b) = 2/5a - b - a + 3/5b = - 3/5a - 2/5b = -1/5(3a + 2b)