Simplify the following:
–3(x + 3) + 4x
d + 3cd – 7c + 3cd + 2c
xy + 4x – 3xy – x
ab – 2ac + cb
4t + 10t
–4(5x)
–10x – x
4 + 7(x + 3)
5(–2xy)
–k + 3(4k –1) + 2
6(–2y) – 9 + 4(–2y + 6)
5(b – 4) + 12