(1целых-1/4+3/8):3/4-1/2
(1 - 1/4 + 3/8) / 3/4 - 1/2 = (8/8 - 2/8 + 3/8) /6/8 - 1/2 = 9/8 / 6/8 - 1/2 = 9/6 - 1/2 = 1 1/2 - 1/2 = 1