Divide into factors.

a) [[$ ax + ay + bx + by $]]



Answer: [[$ ax + ay + bx + by = $]]

b) [[$ ax - bx - ay - by $]]



Answer: [[$ ax - bx - ay - by = $]]

c) [[$ x^2 + ax + bx + ab $]]



Answer: [[$ x^2 + ax + bx + ab = $]]

d) [[$ x^2 + ax - bx - ab $]]



Answer: [[$ x^2 + ax - bx - ab = $]]