X=-7y^2

Solution for X=-7y^2 equation:

X=-7X^2

We move all terms to the left:

X-(-7X^2)=0

We get rid of parentheses

7X^2+X=0

a = 7; b = 1; c = 0;
Δ = b2-4ac
Δ = 12-4·7·0
Δ = 1
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1}=1$
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(1)-1}{2*7}=\frac{-2}{14}
=-1/7
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(1)+1}{2*7}=\frac{0}{14}
=0
$