0=y^2+2y-300

Solution for 0=y^2+2y-300 equation:

0=y^2+2y-300

We move all terms to the left:

0-(y^2+2y-300)=0

We add all the numbers together, and all the variables

-(y^2+2y-300)=0

We get rid of parentheses

-y^2-2y+300=0

We add all the numbers together, and all the variables

-1y^2-2y+300=0

a = -1; b = -2; c = +300;
Δ = b2-4ac
Δ = -22-4·(-1)·300
Δ = 1204
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:

$\sqrt{\Delta}=\sqrt{1204}=\sqrt{4*301}=\sqrt{4}*\sqrt{301}=2\sqrt{301}$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-2)-2\sqrt{301}}{2*-1}=\frac{2-2\sqrt{301}}{-2}
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-2)+2\sqrt{301}}{2*-1}=\frac{2+2\sqrt{301}}{-2}
$