1) 2(a+b)+3(a+b)+2a=2a+2b+3a+3b+2a= 7a+5b
2) 5(x-z)-2(x+z)=5x - 5z -2x - 2z= 3x - 7z
3) 2(2r-3s)-3(r-2s)=4r - 6s - 3r +6s= r
4) 6(2a+c)+2(6a-c)-4c= 12a+6c+12a - 2c=24a+4c
5) b(m-7)-7b=bm - 7b - 7b= bm - 14b
6) x(c+1)+c(x-1)=xc+x+xc - c= 2xc+x - c
7) y(x-4)+x(3-y)=yx - 4y+3x - yx= - 4y+3x