(3x)(-3x)=x

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

(3x)(-3x)=x

We move all terms to the left:

(3x)(-3x)-(x)=0

We add all the numbers together, and all the variables

-1x+3x(-3x)=0

We multiply parentheses

-9x^2-1x=0

a = -9; b = -1; c = 0;
Δ = b2-4ac
Δ = -12-4·(-9)·0
Δ = 1
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1}=1$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-1)-1}{2*-9}=\frac{0}{-18}
=0
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-1)+1}{2*-9}=\frac{2}{-18}
=-1/9
$