Bonjour
20-4x=16
- 4x = 16 - 20
- 4x = - 4
x = 4/4
x = 1
100+2x=175
2x = 175 - 100
2x = 75
x = 75/2
3(x+3)=21
3x + 9 = 21
3x = 21 - 9
3x = 12
x = 12/3
x = 4
56=2x+6
2x = 56 - 6
2x = 50
x = 50/2
x = 25
120=4x+40
4x = 120 - 40
4x = 80
x = 80/4
x = 20
8x+100=124
8x = 124 - 100
8x = 24
x = 24/8
x = 3
75+4x=150+x
4x - x = 150 - 75
3x = 75
x = 75/3
x = 25.