Which is a zero of the quadratic function f (x) = 16x2 32x - 9?

A zero of a function is the value of x for which f (x) = 0

f (x) = 16x^2 + 32x - 9 = 0

16x^2 - 4x + 36x - 9 = 0

(16x^2 - 4x) + (36x - 9) = 0

4x (4x - 1) + 9 (4x - 1) = 0

(4x + 9) (4x - 1) = 0

4x + 9 = 0 and 4x - 1 = 0

4x = - 9 and 4x = 1

x = - 9/4 and x = 1/4