Remove the brackets and simplify.

a) [[$ 2(x +1) + 3(x + 2) =$]]

b) [[$x(x +1) + 2(x + 3) =$]]

c) [[$ -(x - 4) + 3(-x +1) =$]]

d) [[$3x(x - 2) + 5(x^2 -x) =$]]