-10x^2-10x+140=0

Solution for -10x^2-10x+140=0 equation:

-10x^2-10x+140=0

a = -10; b = -10; c = +140;
Δ = b2-4ac
Δ = -102-4·(-10)·140
Δ = 5700
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:

$\sqrt{\Delta}=\sqrt{5700}=\sqrt{100*57}=\sqrt{100}*\sqrt{57}=10\sqrt{57}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-10)-10\sqrt{57}}{2*-10}=\frac{10-10\sqrt{57}}{-20}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-10)+10\sqrt{57}}{2*-10}=\frac{10+10\sqrt{57}}{-20}
$