X + 3 X = 4X
3 X + 1 = 8
X - 2+ 9 X = 4
X = 2
X - 0 = X + 0
X:2 + 3X = 1
X + 7 X = 8 + X
X + X = 2X
5 X + 1 X = 6 X
A + 3 + 2 A = 5
X - X + X = X
5X - X = 4X
