What is the value of "c" in the standard form of form of the parabola that has vertex of (2, 18) and roots of -1 and 5? "c"=[1]

Question

What is the value of "c" in the standard form of form of the parabola that has vertex of (2, 18) and roots of -1 and 5?

"c"=[1]

Thanks in advance!

Answer 1

f(x) = a(x - 2)² + 18

f(5) = 0

0 = a(5 - 2)² + 18

Can you solve for a and answer?