0=2y^2-56

Solution for 0=2y^2-56 equation:

0=2y^2-56

We move all terms to the left:

0-(2y^2-56)=0

We add all the numbers together, and all the variables

-(2y^2-56)=0

We get rid of parentheses

-2y^2+56=0

a = -2; b = 0; c = +56;
Δ = b2-4ac
Δ = 02-4·(-2)·56
Δ = 448
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:

$\sqrt{\Delta}=\sqrt{448}=\sqrt{64*7}=\sqrt{64}*\sqrt{7}=8\sqrt{7}$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-8\sqrt{7}}{2*-2}=\frac{0-8\sqrt{7}}{-4}
=-\frac{8\sqrt{7}}{-4}
=-\frac{2\sqrt{7}}{-1}
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+8\sqrt{7}}{2*-2}=\frac{0+8\sqrt{7}}{-4}
=\frac{8\sqrt{7}}{-4}
=\frac{2\sqrt{7}}{-1}
$