(m-7)-7b m(r-3)-r(m-5)x(c+1)+c(x-1) a(1-b)-a(1+b)y(x-4)+x(3-y) b(2d-5)-b(d+5

(m-7)-7b =m-7-7b
m(r-3)-r(m-5)x(c+1)+c(x-1) = mr-m3-rm+r5)x(c+1+cx-c)
a(1-b)-a(1+b)y(x-4)+x(3-y)=(a1-ab-a-ab)*(yx-y4)+x3-yx
b(2d-5)-b(d+5) = b2d-5b-bd-5b