The graph of a quadratic function intersects the x-axis at -3 and 5.

What is a possible equation for f(x) ?

What is a possible equation for f(x) ?

**Work backwards from the solutions to the equation.**

x = -3 and x = 5

x + 3 = 0 and x - 5 = 0 {added 3 and subtracted 5 in the two equations}

(x + 3)(x - 5) = 0 {multiplied the two binomials and set equal to zero}

x² - 2x - 15 = 0 {used distributive property / FOIL method}

**f(x) = x² - 2x - 15**{replaced 0 with f(x)}