How do I mutliply the following;
(4x2+3x-3)(4x2+3x-3)
Multiply each term of the left group within parentheses by each term in the right group. That will result in nine terms. Some of them can be combined, if they involve the same power of x.
In your case, you get
16 x^4 + 12x^3 -12x^2 +12x^3 +9x^2 -9x -12x^2 -9x +9
Now combine "like" terms
16x^4 + 24x^3 -..x^2 + ..x +9
Fill in the rest.