Pleeeeeeease help me! However helps me first gets brainliest points!

Simplify the following algebraic expressions:
a. - 6x + 5 + 12x -6
b. 2(x - 9) + 6(-x + 2) + 4x
c. 3x2 + 12 + 9x - 20 + 6x2 - x
d. (x + 2)(x + 4) + (x + 5)(-x - 1)
e. (x+8)(x+9)+(x+1)(-x-6)