Solve 318=r^2

$$318 = r ^ { 2 }$$

Solve for r

$$r=\sqrt{318}\approx 17.8325545$$

$$r=-\sqrt{318}\approx -17.8325545$$

Steps by Finding Square Root

Swap sides so that all variable terms are on the left hand side.

$$r^{2}=318$$

Take the square root of both sides of the equation.

$$r=\sqrt{318} r=-\sqrt{318}$$

Steps Using the Quadratic Formula

Swap sides so that all variable terms are on the left hand side.

$$r^{2}=318$$

Subtract 318 from both sides.

$$r^{2}-318=0$$

This equation is in standard form: ax^{2}+bx+c=0. Substitute 1 for a, 0 for b, and -318 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.

$$r=\frac{0±\sqrt{0^{2}-4\left(-318\right)}}{2}$$

Square 0.

$$r=\frac{0±\sqrt{-4\left(-318\right)}}{2}$$

Multiply -4 times -318.

$$r=\frac{0±\sqrt{1272}}{2}$$

Take the square root of 1272.

$$r=\frac{0±2\sqrt{318}}{2}$$

Now solve the equation r=\frac{0±2\sqrt{318}}{2} when ± is plus.

$$r=\sqrt{318}$$

Now solve the equation r=\frac{0±2\sqrt{318}}{2} when ± is minus.

$$r=-\sqrt{318}$$

The equation is now solved.

$$r=\sqrt{318} r=-\sqrt{318}$$