20x+(18-x)x=0

Solution for 20x+(18-x)x=0 equation:

20x+(18-x)x=0

We add all the numbers together, and all the variables

20x+(-1x+18)x=0

We multiply parentheses

-1x^2+20x+18x=0

We add all the numbers together, and all the variables

-1x^2+38x=0

a = -1; b = 38; c = 0;
Δ = b2-4ac
Δ = 382-4·(-1)·0
Δ = 1444
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1444}=38$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(38)-38}{2*-1}=\frac{-76}{-2}
=+38
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(38)+38}{2*-1}=\frac{0}{-2}
=0
$