980x^2-19.6-784=0

Solution for 980x^2-19.6-784=0 equation:

980x^2-19.6-784=0

We add all the numbers together, and all the variables

980x^2-803.6=0

a = 980; b = 0; c = -803.6;
Δ = b2-4ac
Δ = 02-4·980·(-803.6)
Δ = 3150112
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:

$\sqrt{\Delta}=\sqrt{3150112}=\sqrt{38416*82}=\sqrt{38416}*\sqrt{82}=196\sqrt{82}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-196\sqrt{82}}{2*980}=\frac{0-196\sqrt{82}}{1960}
=-\frac{196\sqrt{82}}{1960}
=-\frac{\sqrt{82}}{10}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+196\sqrt{82}}{2*980}=\frac{0+196\sqrt{82}}{1960}
=\frac{196\sqrt{82}}{1960}
=\frac{\sqrt{82}}{10}
$