2x2+-20x=-18

Solution for 2x2+-20x=-18 equation:

2x^2+-20x=-18

We move all terms to the left:

2x^2+-20x-(-18)=0

We add all the numbers together, and all the variables

2x^2-20x+18=0

a = 2; b = -20; c = +18;
Δ = b2-4ac
Δ = -202-4·2·18
Δ = 256
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{256}=16$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-20)-16}{2*2}=\frac{4}{4}
=1
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-20)+16}{2*2}=\frac{36}{4}
=9
$