119
(20x+63-24)/36 = (48x+18x+16)/36
46x = 23
x = 23/46 = 1/2
120
(1-33x)/9 = (30x-9+9x+2)/9
72x = 8
x = 1/9
121
(18x-12x-36)/24 = (9-8x+48x-4-7)/24
34x = -34
x = -1
122
(72x-33)/36 = (18x+10+2)/36
54x = 45
6x = 5
x = 5/6