Expand and simplify the following

a) (x+3)^2
b) (3x-6)^2
c) (x-4)^2

a) (x+3)^2 expands to x^2 + 6x + 9.

b) (3x-6)^2 expands to 9x^2 - 36x + 36.

c) (x-4)^2 expands to x^2 - 8x + 16.