2x-3x(x-40)=x

Solution for 2x-3x(x-40)=x equation:

2x-3x(x-40)=x

We move all terms to the left:

2x-3x(x-40)-(x)=0

We add all the numbers together, and all the variables

x-3x(x-40)=0

We multiply parentheses

-3x^2+x+120x=0

We add all the numbers together, and all the variables

-3x^2+121x=0

a = -3; b = 121; c = 0;
Δ = b2-4ac
Δ = 1212-4·(-3)·0
Δ = 14641
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{14641}=121$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(121)-121}{2*-3}=\frac{-242}{-6}
=40+1/3
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(121)+121}{2*-3}=\frac{0}{-6}
=0
$