X^2-10x-225=0

Solution for X^2-10x-225=0 equation:

X^2-10X-225=0

a = 1; b = -10; c = -225;
Δ = b2-4ac
Δ = -102-4·1·(-225)
Δ = 1000
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:

$\sqrt{\Delta}=\sqrt{1000}=\sqrt{100*10}=\sqrt{100}*\sqrt{10}=10\sqrt{10}$
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-10)-10\sqrt{10}}{2*1}=\frac{10-10\sqrt{10}}{2}
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-10)+10\sqrt{10}}{2*1}=\frac{10+10\sqrt{10}}{2}
$