10x2-30x-100=0

Solution for 10x2-30x-100=0 equation:

10x^2-30x-100=0

a = 10; b = -30; c = -100;
Δ = b2-4ac
Δ = -302-4·10·(-100)
Δ = 4900
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{4900}=70$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-30)-70}{2*10}=\frac{-40}{20}
=-2
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-30)+70}{2*10}=\frac{100}{20}
=5
$