Solve y^2=(-4/5)(-15)+48

$$y ^ { 2 } = ( - \frac { 4 } { 5 } ) ( - 15 ) + 48$$

Solve for y

$$y=2\sqrt{15}\approx 7.745966692$$

$$y=-2\sqrt{15}\approx -7.745966692$$

Steps by Finding Square Root

Multiply -\frac{4}{5} and -15 to get 12.

$$y^{2}=12+48$$

Add 12 and 48 to get 60.

$$y^{2}=60$$

Take the square root of both sides of the equation.

$$y=2\sqrt{15} y=-2\sqrt{15}$$

Steps Using the Quadratic Formula

Multiply -\frac{4}{5} and -15 to get 12.

$$y^{2}=12+48$$

Add 12 and 48 to get 60.

$$y^{2}=60$$

Subtract 60 from both sides.

$$y^{2}-60=0$$

This equation is in standard form: ax^{2}+bx+c=0. Substitute 1 for a, 0 for b, and -60 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.

$$y=\frac{0±\sqrt{0^{2}-4\left(-60\right)}}{2}$$

Square 0.

$$y=\frac{0±\sqrt{-4\left(-60\right)}}{2}$$

Multiply -4 times -60.

$$y=\frac{0±\sqrt{240}}{2}$$

Take the square root of 240.

$$y=\frac{0±4\sqrt{15}}{2}$$

Now solve the equation y=\frac{0±4\sqrt{15}}{2} when ± is plus.

$$y=2\sqrt{15}$$

Now solve the equation y=\frac{0±4\sqrt{15}}{2} when ± is minus.

$$y=-2\sqrt{15}$$

The equation is now solved.

$$y=2\sqrt{15} y=-2\sqrt{15}$$