Expand the following:

Q1) (x + y)(x^2 - xy +y^2)
Q2) (x^2 - 4)(x^2 - 2x + 1)
Q3) (5 - 2a)(2 - 3a - a^2)
Q4) (1 - 2x)(3 + 2x - x^2)

Solve these questions correct with detailed workings and earn points!!!
The lucky person with the best answer will be voted as the "BEST ANSWER".
Voting of the best answer will take place after 12hours!!.