-245=-5y^2

Solution for -245=-5y^2 equation:

-245=-5y^2

We move all terms to the left:

-245-(-5y^2)=0

We get rid of parentheses

5y^2-245=0

a = 5; b = 0; c = -245;
Δ = b2-4ac
Δ = 02-4·5·(-245)
Δ = 4900
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{4900}=70$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-70}{2*5}=\frac{-70}{10}
=-7
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+70}{2*5}=\frac{70}{10}
=7
$