100x2+90x-10=0

Solution for 100x2+90x-10=0 equation:

100x^2+90x-10=0

a = 100; b = 90; c = -10;
Δ = b2-4ac
Δ = 902-4·100·(-10)
Δ = 12100
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{12100}=110$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(90)-110}{2*100}=\frac{-200}{200}
=-1
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(90)+110}{2*100}=\frac{20}{200}
=1/10
$