-40x^2+245x+30=0

Solution for -40x^2+245x+30=0 equation:

-40x^2+245x+30=0

a = -40; b = 245; c = +30;
Δ = b2-4ac
Δ = 2452-4·(-40)·30
Δ = 64825
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:

$\sqrt{\Delta}=\sqrt{64825}=\sqrt{25*2593}=\sqrt{25}*\sqrt{2593}=5\sqrt{2593}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(245)-5\sqrt{2593}}{2*-40}=\frac{-245-5\sqrt{2593}}{-80}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(245)+5\sqrt{2593}}{2*-40}=\frac{-245+5\sqrt{2593}}{-80}
$