1. 11 - 2x = 5 - 3x
= 3x - 2x = 5 - 11 (we bring all the like terms at one side together)
= x = -6
2. -40 - 16x = -6 - 15x
= -40 + 6 = 16x - 15x
= -34 = x
3. 20 - 6x = 20 - 4x
= 20 - 20 = 6x - 4x
= 0 = 2x
= 0/2 = x
= 0 = x
4. 5 - 2x = 5x - 9
= 5 + 9 = 5x + 2x
= 14 = 7x
= 14/7 = x
= 2 = x