Вычислите:
1) (-3/14 -8/21) : 20/21
2) 3/8 : (-5/8)-(-2 1/4):(-1 4/11)
3) (-4 1/12+ 3 9/10): 3 3/10
4) (11/14-5/6):(11/14-3/4)

Помогите! Дам 15 баллов!

пожалуйста. И тебе спасибо

1) (-3/14 -8/21) : 20/21 = - 21/32     -(3/14 + 8/21) =  - (18/84 + 32/84) = -50/84 = -25/42     -25/42:20/21 = -25/42*21/20 = - 5/8 2) 3/8 : (-5/8) - (-2 1/4):(-1 4/11) = -2 131/260                   3/8 : (-5/8) = - 3/8*8/5 = -3/5        (-2 1/4):(-1 4/11)  = (-9/4):(-13/11) = 9/4*11/13 = 99/52 = 1 47/52- 3/5 - 1 47/52 = -(3/5 + 1 47/52) = - (156/260 + 1 235/260) = - 1 391/260 =           = -2 131/260 3) (-4 1/12+ 3 9/10): 3 3/10 = -2/11     - 4 1/12+ 3 9/10 = -(4 1/2 - 3 9/10) = - (4 5/10 - 3 9/10) = - (3 15/10 - 3 9/10) =      = - 6/10 = -3/5(-3/5):3 3/10 = -3/5 : 33/10 = - 3/5*10/33 = -2/11 4) (11/14-5/6):(11/14-3/4) = - 1 1/311/14-5/6 = 33/42 - 35/42 = - 2/42 = - 1/2111/14-3/4 = 22/28 - 21/28 = 1/28 -1/21:1/28 = -1/21*28/1= -4/3 = -1 1/3