(X2)-20+(0.5*y)=0

Solution for (X2)-20+(0.5*y)=0 equation:

(X2)-20+(0.5X)=0

We add all the numbers together, and all the variables

X2+(+0.5X)-20=0

We add all the numbers together, and all the variables

X^2+(+0.5X)-20=0

We get rid of parentheses

X^2+0.5X-20=0

a = 1; b = 0.5; c = -20;
Δ = b2-4ac
Δ = 0.52-4·1·(-20)
Δ = 80.25
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{-(0.5)-\sqrt{80.25}}{2*1}=\frac{-0.5-\sqrt{80.25}}{2}
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0.5)+\sqrt{80.25}}{2*1}=\frac{-0.5+\sqrt{80.25}}{2}
$