Find the Roots (Zeros) f(x)=x(x-4)(x+9)

$f (x) = x (x - 4) (x + 9)$

Step 1

Set $x (x - 4) (x + 9)$ equal to $0$ .

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

Step 2

Solve for $x$ .

If any individual factor on the left side of the equation is equal to $0$ , the entire expression will be equal to $0$ .

$x = 0$

$x - 4 = 0$

$x + 9 = 0$

Set $x$ equal to $0$ .

$x = 0$

Set $x - 4$ equal to $0$ and solve for $x$ .

Set $x - 4$ equal to $0$ .

$x - 4 = 0$

Add $4$ to both sides of the equation.

$x = 4$

Set $x + 9$ equal to $0$ and solve for $x$ .

Set $x + 9$ equal to $0$ .

$x + 9 = 0$

Subtract $9$ from both sides of the equation.

$x = - 9$

The final solution is all the values that make $x (x - 4) (x + 9) = 0$ true.

$x = 0, 4, - 9$

Step 3