4a+3a-2a=5a
2b-b+0.5b=1.5b
10x-(7x+x)=2x
6x-1.5x=4.5x
8x+4x-8x=4x
7.5x-x+2.5=6.5x+2.5
5x-(3x-2.4x)=4.4x