a) 7ax2 + (a – 3ax3) – (5a + ax3)

b) (13ab + 5a) – (15ab + 7a2 – 3a) – (-2ab + a2)


c) (x2 + 3) + ( – x + 2) – (x2 – 1) + (-7x2 + 2x – 2)


d) (x + 4) – (x – 2) + (4x – 5) – (7x + 10)



e) 2x – (y + 1 – 3x) – (2xy + 7y – 2) + (-5y + 7x + 2x