Вычислите а)-7/ целых 5/12+4/9) б)3/16*(-4/15)-11/12 и поделить это на 1 целую 5/6 с объяснениями!

А) - 7/18 - (-4 5/12 + 4/9) = 3 7/12
1) - 4 5/12 + 4/9 = - 4 15/36 + 16/36 = - (4 15/36 - 16/36) = - (3 51/36 - 16/36) = - 3 35/36
2) - 7/18 - (- 3 35/36) = - 14/36 + 3 35/36 = 3 35/36 - 14/36 = 3 21/36 = 3 7/12

б) 3/16 * (-4/15) - 11/12 : 1 5/6 = - 11/20
1) 3/16 * (-4/15) = - 1/20
2) 11/12 : 1 5/6 = 11/12 : 11/6 = 11/12 * 6/11 = 6/12 = 1/2
3) - 1/20 - 1/2 = - 1/20 - 10/20 = - 11/20