I need to solve for a, b, c, and d for a cubic equation with points (2,24), (-2,0), (0,0), and (3,0). I plugged them into the equation getting these equations:

8a + 4b + 2c + d = 24

-8a + 4b + -2c + d = 0

27a + 9b + 3c = 0

d = 0

I put the numbers into a matrix and tried to solve with Gaussian elimination but I couldn't get rid of the 27 without a huge mess. I don't know any other way to do it. Please help.