1)2m+5n-4n-6m+3n+m=2m-6m+m+5n-4n+3n=-3m+4n
2)3m+2n-5n-4m+7n-m =3m-4m-m+2n-5n+7n=-2m+4n
3)6x-3y+8y-4x+7=6x-4x-3y+8y+7=2x+5y+7
4)5x-7y+5y-2x+4 =5x-2x-7y+5y+4=3x-2y+4
5) 5(2x-3y)+2(15y-3x)=10x-15y+30y-6x=10x-6x-15y+30y=4x+15y
6)4(2x-3y)-8(x+2y)=8x-12y-8x-16y=8x-8x-12y-16y=-28y