Solve 5x(x)=45

$$5 x ( x ) = 45$$

Solve for x

$$x=3$$

$$x=-3$$

Steps by Finding Square Root

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

$$5x^{2}=45$$

Divide both sides by 5.

$$x^{2}=\frac{45}{5}$$

Divide 45 by 5 to get 9.

$$x^{2}=9$$

Take the square root of both sides of the equation.

$$x=3 x=-3$$

Steps Using the Quadratic Formula

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

$$5x^{2}=45$$

Subtract 45 from both sides.

$$5x^{2}-45=0$$

This equation is in standard form: ax^{2}+bx+c=0. Substitute 5 for a, 0 for b, and -45 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.

$$x=\frac{0±\sqrt{0^{2}-4\times 5\left(-45\right)}}{2\times 5}$$

Square 0.

$$x=\frac{0±\sqrt{-4\times 5\left(-45\right)}}{2\times 5}$$

Multiply -4 times 5.

$$x=\frac{0±\sqrt{-20\left(-45\right)}}{2\times 5}$$

Multiply -20 times -45.

$$x=\frac{0±\sqrt{900}}{2\times 5}$$

Take the square root of 900.

$$x=\frac{0±30}{2\times 5}$$

Multiply 2 times 5.

$$x=\frac{0±30}{10}$$

Now solve the equation x=\frac{0±30}{10} when ± is plus. Divide 30 by 10.

$$x=3$$

Now solve the equation x=\frac{0±30}{10} when ± is minus. Divide -30 by 10.

$$x=-3$$

The equation is now solved.

$$x=3 x=-3$$