3x(6+4)=3x6+3x4
3x(6+4)=3x10
5x(3-2)=5x3-5x2
5x(3-2)=5x1
4x5=4x2+4x3
3x2=3x8-3x6
2x8-2x4=2x(8-4)
5x3+5x4=5x(3+4)