x^2+87x-90=0

Solution for x^2+87x-90=0 equation:

x^2+87x-90=0

a = 1; b = 87; c = -90;
Δ = b2-4ac
Δ = 872-4·1·(-90)
Δ = 7929
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:

$\sqrt{\Delta}=\sqrt{7929}=\sqrt{9*881}=\sqrt{9}*\sqrt{881}=3\sqrt{881}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(87)-3\sqrt{881}}{2*1}=\frac{-87-3\sqrt{881}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(87)+3\sqrt{881}}{2*1}=\frac{-87+3\sqrt{881}}{2}
$