Question

(x+y)(a+b) - (y+z)(a+b)

plz answer with full working
as it is very urgent

Answer 1

= (xa+xb+ya+yb )-(ya+yb+za+zb)
= xa+xb+ya+yb-ya-yb-za-zb
= xa+xb-za-zb

Answer 2

= (x+y)(a+b) - (y+z)(a+b)
= ax + bx + ay + by - (ay + by + az + bz)
= ax + bx + ay + by - ay - by - az - bz
= ax + bx - az - bz
= x(a+b) - z (a+b)
= (a+b)(x-z)