Find a formula for a quadratic function whose graph has x-intercepts at (1, 0) and (5, 0), and y-intercept at (0, 7).
y = a(x-1)(x-5)
7 = 1(-1)(-5)
7 = 5a
a = 7/5
Therefore, the quadratic formula is y = (7/5)(x-1)(x-5)