-20x2+1400x+36000=0

Solution for -20x2+1400x+36000=0 equation:

-20x^2+1400x+36000=0

a = -20; b = 1400; c = +36000;
Δ = b2-4ac
Δ = 14002-4·(-20)·36000
Δ = 4840000
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{4840000}=2200$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(1400)-2200}{2*-20}=\frac{-3600}{-40}
=+90
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(1400)+2200}{2*-20}=\frac{800}{-40}
=-20
$