3x(2x-1)+(2x-1)=0

Solution for 3x(2x-1)+(2x-1)=0 equation:

3x(2x-1)+(2x-1)=0

We multiply parentheses

6x^2-3x+(2x-1)=0

We get rid of parentheses

6x^2-3x+2x-1=0

We add all the numbers together, and all the variables

6x^2-1x-1=0

a = 6; b = -1; c = -1;
Δ = b2-4ac
Δ = -12-4·6·(-1)
Δ = 25
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{25}=5$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-1)-5}{2*6}=\frac{-4}{12}
=-1/3
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-1)+5}{2*6}=\frac{6}{12}
=1/2
$