-4y^2=-60

Solution for -4y^2=-60 equation:

-4y^2=-60

We move all terms to the left:

-4y^2-(-60)=0

We add all the numbers together, and all the variables

-4y^2+60=0

a = -4; b = 0; c = +60;
Δ = b2-4ac
Δ = 02-4·(-4)·60
Δ = 960
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{960}=\sqrt{64*15}=\sqrt{64}*\sqrt{15}=8\sqrt{15}$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-8\sqrt{15}}{2*-4}=\frac{0-8\sqrt{15}}{-8}
=-\frac{8\sqrt{15}}{-8}
=-\frac{\sqrt{15}}{-1}
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+8\sqrt{15}}{2*-4}=\frac{0+8\sqrt{15}}{-8}
=\frac{8\sqrt{15}}{-8}
=\frac{\sqrt{15}}{-1}
$