X2+17x-18=0

Solution for X2+17x-18=0 equation:

X2+17X-18=0

We add all the numbers together, and all the variables

X^2+17X-18=0

a = 1; b = 17; c = -18;
Δ = b2-4ac
Δ = 172-4·1·(-18)
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{-(17)-19}{2*1}=\frac{-36}{2}
=-18
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(17)+19}{2*1}=\frac{2}{2}
=1
$