x^2+70x-225=0

Solution for x^2+70x-225=0 equation:

x^2+70x-225=0

a = 1; b = 70; c = -225;
Δ = b2-4ac
Δ = 702-4·1·(-225)
Δ = 5800
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:

$\sqrt{\Delta}=\sqrt{5800}=\sqrt{100*58}=\sqrt{100}*\sqrt{58}=10\sqrt{58}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(70)-10\sqrt{58}}{2*1}=\frac{-70-10\sqrt{58}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(70)+10\sqrt{58}}{2*1}=\frac{-70+10\sqrt{58}}{2}
$