-10x2+140x+150=0

Solution for -10x2+140x+150=0 equation:

-10x^2+140x+150=0

a = -10; b = 140; c = +150;
Δ = b2-4ac
Δ = 1402-4·(-10)·150
Δ = 25600
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{25600}=160$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(140)-160}{2*-10}=\frac{-300}{-20}
=+15
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(140)+160}{2*-10}=\frac{20}{-20}
=-1
$