-4x^2+160x+250=0

Solution for -4x^2+160x+250=0 equation:

-4x^2+160x+250=0

a = -4; b = 160; c = +250;
Δ = b2-4ac
Δ = 1602-4·(-4)·250
Δ = 29600
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:

$\sqrt{\Delta}=\sqrt{29600}=\sqrt{400*74}=\sqrt{400}*\sqrt{74}=20\sqrt{74}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(160)-20\sqrt{74}}{2*-4}=\frac{-160-20\sqrt{74}}{-8}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(160)+20\sqrt{74}}{2*-4}=\frac{-160+20\sqrt{74}}{-8}
$