X2+y=784

Solution for X2+y=784 equation:

X2+X=784

We move all terms to the left:

X2+X-(784)=0

We add all the numbers together, and all the variables

X^2+X-784=0

a = 1; b = 1; c = -784;
Δ = b2-4ac
Δ = 12-4·1·(-784)
Δ = 3137
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(1)-\sqrt{3137}}{2*1}=\frac{-1-\sqrt{3137}}{2}
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(1)+\sqrt{3137}}{2*1}=\frac{-1+\sqrt{3137}}{2}
$