is it with fractions

1/3a + 1/2b - 3/4 + 1/2b - 2/3b + 5/6a = (1/3a + 5/6a) + (1/2b + 1/2b - 2/3b) - 3/4 = (2/6a + 5/6a) + (3/6b + 3/6b - 4/6b) - 3/4 = 7/6a + 1/3b - 3/4 <==