Tìm x, biết

a)
3 1/3.x + 16 3/4 = -13.25
10/3x + 67/4 = -53/4
10/3x = -120/4 - 67/4
10/3x = -187/4
x = -187/4 * 3/10
x = -561/40

b)
2 1/5 + 3/5x = 3/4
11/5 + 3/5x = 3/4
3/5x = 3/4 - 11/5
3/5x = 15/20 - 44/20
3/5x = -29/20
x = -29/20 * 5/3
x = -29/12

c)
(2.4x - 36) / 1 5/7 = -1
(12/5x - 36) / 12/7 = -1
(12/5x - 36) / 12/7 = -7/7
12/5x - 36 = -12
12/5x = 24
x = 24 * 5/12
x = 10

d)
5/6 - x = -7/12 + 2/3
5/6 + 7/12 = x + 2/3
10/12 + 7/12 = x + 8/12
17/12 = x + 2/3
17/12 - 2/3 = x
17/12 - 8/12 = x
9/12 = x
x = 3/4