What is the first step when rewriting y = 3x2 + 9x – 18 in the form y = a(x – h)2 + k? 3 must be factored from 3x2 + 9x x must be factored from 3x2 + 9x 9 must be factored from 9x – 18 3 must be factored from 3x2 – 18