Solve 5x(x)=320

$$5 x ( x ) = 320$$

Solve for x

$$x=8$$

$$x=-8$$

Steps by Finding Square Root

Multiply x and x to get x^{2}.

$$5x^{2}=320$$

Divide both sides by 5.

$$x^{2}=\frac{320}{5}$$

Divide 320 by 5 to get 64.

$$x^{2}=64$$

Take the square root of both sides of the equation.

$$x=8 x=-8$$

Steps Using the Quadratic Formula

Multiply x and x to get x^{2}.

$$5x^{2}=320$$

Subtract 320 from both sides.

$$5x^{2}-320=0$$

This equation is in standard form: ax^{2}+bx+c=0. Substitute 5 for a, 0 for b, and -320 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.

$$x=\frac{0±\sqrt{0^{2}-4\times 5\left(-320\right)}}{2\times 5}$$

Square 0.

$$x=\frac{0±\sqrt{-4\times 5\left(-320\right)}}{2\times 5}$$

Multiply -4 times 5.

$$x=\frac{0±\sqrt{-20\left(-320\right)}}{2\times 5}$$

Multiply -20 times -320.

$$x=\frac{0±\sqrt{6400}}{2\times 5}$$

Take the square root of 6400.

$$x=\frac{0±80}{2\times 5}$$

Multiply 2 times 5.

$$x=\frac{0±80}{10}$$

Now solve the equation x=\frac{0±80}{10} when ± is plus. Divide 80 by 10.

$$x=8$$

Now solve the equation x=\frac{0±80}{10} when ± is minus. Divide -80 by 10.

$$x=-8$$

The equation is now solved.

$$x=8 x=-8$$