Решить уравнение в)

7 - 1/2a + (1/2a - 5 1/2) = 2a + 3/4 - (1/2 + 1/2a) 7 - 1/2a + 1/2a - 11/2 = 2a + 3/4 - 1/2 - 1/2a 7 - 11/2 = 2a - 1/2a + 3/4 - 1/2 14/2 - 11/2 = 3/2a + 2/4 - 1/4 3/2 = 3/2a + 1/4 3/2 - 1/4 = 3/2a 6/4 - 1/4 = 3/2a 5/4 = 3/2a (5/4)*(2/3) = a 10/12 = a a = 5/6.