a 3.x-2.x=84-24
x=60
b 12x-91=3636:36
12x-91=101
12x=101+91
12x=192
x=192:12=16
3x + 24 = 2x + 84
=> x = 84 - 24
x = 60
3636 : ( 12x - 91 ) = 36
12x - 91 = 101
12x = 101 + 91
12x = 192
x = 16
3x + 24 = 2x + 84
x = 84 - 24
x = 60
3636 : ( 12x - 91 ) = 36
12x - 91 = 3636 : 36
12x - 91 = 101
12x = 101 + 91
12x = 192
x = 192 : 12
x = 16