Question

1) -a-(x-y)+(-b+c)
2) (a-b)-(c-d)
3) 2a(3a-8b)
4) 4b-(15b+y0-(y-10b)

Answer 1

1) -a-x+y-b+c
2) a-b-c+b=a-c(b и -b сокращается)
3)6a^2-16ab
4)4b-15b-y0+y-10b=-b