-10x2+4x+11=0

Solution for -10x2+4x+11=0 equation:

-10x^2+4x+11=0

a = -10; b = 4; c = +11;
Δ = b2-4ac
Δ = 42-4·(-10)·11
Δ = 456
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:

$\sqrt{\Delta}=\sqrt{456}=\sqrt{4*114}=\sqrt{4}*\sqrt{114}=2\sqrt{114}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(4)-2\sqrt{114}}{2*-10}=\frac{-4-2\sqrt{114}}{-20}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(4)+2\sqrt{114}}{2*-10}=\frac{-4+2\sqrt{114}}{-20}
$