Then standard form for which you are looking is y = Ax2 + Bx + C.
y-intercept of 101 means C = 101
Since the vertex is at (-6,-7)
2A(-6) + B = 0 => -12A + B = 0(The derivative is 0 at the vertex) and
36A - 6B + 101 = -7 => 6A - B = -18
Add the 2 equations which will eliminate B, solve for A, use either equation to compute A and you will have your solution.