Ответ:

3a+5a=8a

5-6z+4z=5-2z

-15m+5m+m=-10m+m=-9m

-9p-5+15p-6=-9p+15p-5-6=6p-11

a+(3a-4)=4a-4=4(a-1)

7n-(5+2n)=7n-5+2n=9n-5

-9p-5+15p-6=6p-11

-(2x+5y)-(-3x+4y)=-2x-5y+3x+4y=x-y

b(2a+4)-a(b-3)=2ab+4b-ab+3a=ab+4b+3a