Solve 144/169=r^2

$$\frac { 144 } { 169 } = r ^ { 2 }$$

Solve for r

$$r=\frac{12}{13}\approx 0.923076923$$

$$r=-\frac{12}{13}\approx -0.923076923$$

Steps Using Difference of Squares

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

$$r^{2}=\frac{144}{169}$$

Subtract \frac{144}{169} from both sides.

$$r^{2}-\frac{144}{169}=0$$

Multiply both sides by 169.

$$169r^{2}-144=0$$

Consider 169r^{2}-144. Rewrite 169r^{2}-144 as \left(13r\right)^{2}-12^{2}. The difference of squares can be factored using the rule: a^{2}-b^{2}=\left(a-b\right)\left(a+b\right).

$$\left(13r-12\right)\left(13r+12\right)=0$$

To find equation solutions, solve 13r-12=0 and 13r+12=0.

$$r=\frac{12}{13} r=-\frac{12}{13}$$

Steps by Finding Square Root

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

$$r^{2}=\frac{144}{169}$$

Take the square root of both sides of the equation.

$$r=\frac{12}{13} r=-\frac{12}{13}$$

Steps Using the Quadratic Formula

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

$$r^{2}=\frac{144}{169}$$

Subtract \frac{144}{169} from both sides.

$$r^{2}-\frac{144}{169}=0$$

This equation is in standard form: ax^{2}+bx+c=0. Substitute 1 for a, 0 for b, and -\frac{144}{169} for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.

$$r=\frac{0±\sqrt{0^{2}-4\left(-\frac{144}{169}\right)}}{2}$$

Square 0.

$$r=\frac{0±\sqrt{-4\left(-\frac{144}{169}\right)}}{2}$$

Multiply -4 times -\frac{144}{169}.

$$r=\frac{0±\sqrt{\frac{576}{169}}}{2}$$

Take the square root of \frac{576}{169}.

$$r=\frac{0±\frac{24}{13}}{2}$$

Now solve the equation r=\frac{0±\frac{24}{13}}{2} when ± is plus.

$$r=\frac{12}{13}$$

Now solve the equation r=\frac{0±\frac{24}{13}}{2} when ± is minus.

$$r=-\frac{12}{13}$$

The equation is now solved.

$$r=\frac{12}{13} r=-\frac{12}{13}$$