1.25X^2+480x-1=0

Solution for 1.25X^2+480x-1=0 equation:

1.25X^2+480X-1=0

a = 1.25; b = 480; c = -1;
Δ = b2-4ac
Δ = 4802-4·1.25·(-1)
Δ = 230405
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{-(480)-\sqrt{230405}}{2*1.25}=\frac{-480-\sqrt{230405}}{2.5}
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(480)+\sqrt{230405}}{2*1.25}=\frac{-480+\sqrt{230405}}{2.5}
$