Solve 25x^2=15.6

$$25 { x }^{ 2 } = 15.6$$

Solve for x

$$x=\frac{\sqrt{390}}{25}\approx 0.789936706$$

$$x=-\frac{\sqrt{390}}{25}\approx -0.789936706$$

Steps by Finding Square Root

Divide both sides by 25.

$$x^{2}=\frac{15.6}{25}$$

Expand \frac{15.6}{25} by multiplying both numerator and the denominator by 10.

$$x^{2}=\frac{156}{250}$$

Reduce the fraction \frac{156}{250} to lowest terms by extracting and canceling out 2.

$$x^{2}=\frac{78}{125}$$

Take the square root of both sides of the equation.

$$x=\frac{\sqrt{390}}{25} x=-\frac{\sqrt{390}}{25}$$

Steps Using the Quadratic Formula

Divide both sides by 25.

$$x^{2}=\frac{15.6}{25}$$

Expand \frac{15.6}{25} by multiplying both numerator and the denominator by 10.

$$x^{2}=\frac{156}{250}$$

Reduce the fraction \frac{156}{250} to lowest terms by extracting and canceling out 2.

$$x^{2}=\frac{78}{125}$$

Subtract \frac{78}{125} from both sides.

$$x^{2}-\frac{78}{125}=0$$

This equation is in standard form: ax^{2}+bx+c=0. Substitute 1 for a, 0 for b, and -\frac{78}{125} for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.

$$x=\frac{0±\sqrt{0^{2}-4\left(-\frac{78}{125}\right)}}{2}$$

Square 0.

$$x=\frac{0±\sqrt{-4\left(-\frac{78}{125}\right)}}{2}$$

Multiply -4 times -\frac{78}{125}.

$$x=\frac{0±\sqrt{\frac{312}{125}}}{2}$$

Take the square root of \frac{312}{125}.

$$x=\frac{0±\frac{2\sqrt{390}}{25}}{2}$$

Now solve the equation x=\frac{0±\frac{2\sqrt{390}}{25}}{2} when ± is plus.

$$x=\frac{\sqrt{390}}{25}$$

Now solve the equation x=\frac{0±\frac{2\sqrt{390}}{25}}{2} when ± is minus.

$$x=-\frac{\sqrt{390}}{25}$$

The equation is now solved.

$$x=\frac{\sqrt{390}}{25} x=-\frac{\sqrt{390}}{25}$$