-25x^2+10x+6=0

Solution for -25x^2+10x+6=0 equation:

-25x^2+10x+6=0

a = -25; b = 10; c = +6;
Δ = b2-4ac
Δ = 102-4·(-25)·6
Δ = 700
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:

$\sqrt{\Delta}=\sqrt{700}=\sqrt{100*7}=\sqrt{100}*\sqrt{7}=10\sqrt{7}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(10)-10\sqrt{7}}{2*-25}=\frac{-10-10\sqrt{7}}{-50}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(10)+10\sqrt{7}}{2*-25}=\frac{-10+10\sqrt{7}}{-50}
$