10X^2-130*x-900=0

Solution for 10X^2-130*x-900=0 equation:

10X^2-130X-900=0

a = 10; b = -130; c = -900;
Δ = b2-4ac
Δ = -1302-4·10·(-900)
Δ = 52900
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{52900}=230$
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-130)-230}{2*10}=\frac{-100}{20}
=-5
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-130)+230}{2*10}=\frac{360}{20}
=18
$