x*x-3x-88=0

Solution for x*x-3x-88=0 equation:

x*x-3x-88=0

We add all the numbers together, and all the variables

-3x+x*x-88=0

Wy multiply elements

x^2-3x-88=0

a = 1; b = -3; c = -88;
Δ = b2-4ac
Δ = -32-4·1·(-88)
Δ = 361
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{361}=19$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-3)-19}{2*1}=\frac{-16}{2}
=-8
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-3)+19}{2*1}=\frac{22}{2}
=11
$