Solve for x 0=4x^2-72x

$0 = 4 x^{2} - 72 x$

Step 1

Rewrite the equation as $4 x^{2} - 72 x = 0$ .

$4 x^{2} - 72 x = 0$

Step 2

Factor $4 x$ out of $4 x^{2} - 72 x$ .

Factor $4 x$ out of $4 x^{2}$ .

$4 x (x) - 72 x = 0$

Factor $4 x$ out of $- 72 x$ .

$4 x (x) + 4 x (- 18) = 0$

Factor $4 x$ out of $4 x (x) + 4 x (- 18)$ .

$4 x (x - 18) = 0$

Step 3

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

$x = 0$

$x - 18 = 0$

Step 4

Set $x$ equal to $0$ .

$x = 0$

Step 5

Set $x - 18$ equal to $0$ and solve for $x$ .

Set $x - 18$ equal to $0$ .

$x - 18 = 0$

Add $18$ to both sides of the equation.

$x = 18$

Step 6

The final solution is all the values that make $4 x (x - 18) = 0$ true.

$x = 0, 18$