80+20x=980x^2

Solution for 80+20x=980x^2 equation:

80+20x=980x^2

We move all terms to the left:

80+20x-(980x^2)=0

determiningTheFunctionDomain
-980x^2+20x+80=0

a = -980; b = 20; c = +80;
Δ = b2-4ac
Δ = 202-4·(-980)·80
Δ = 314000
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{314000}=\sqrt{400*785}=\sqrt{400}*\sqrt{785}=20\sqrt{785}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(20)-20\sqrt{785}}{2*-980}=\frac{-20-20\sqrt{785}}{-1960}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(20)+20\sqrt{785}}{2*-980}=\frac{-20+20\sqrt{785}}{-1960}
$