X2+20x=300

Solution for X2+20x=300 equation:

X2+20X=300

We move all terms to the left:

X2+20X-(300)=0

We add all the numbers together, and all the variables

X^2+20X-300=0

a = 1; b = 20; c = -300;
Δ = b2-4ac
Δ = 202-4·1·(-300)
Δ = 1600
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1600}=40$
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(20)-40}{2*1}=\frac{-60}{2}
=-30
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(20)+40}{2*1}=\frac{20}{2}
=10
$