x.7(9x-12)=8x

Solution for x.7(9x-12)=8x equation:

x.7(9x-12)=8x

We move all terms to the left:

x.7(9x-12)-(8x)=0

We add all the numbers together, and all the variables

-8x+x.7(9x-12)=0

We multiply parentheses

9x^2-8x-12x=0

We add all the numbers together, and all the variables

9x^2-20x=0

a = 9; b = -20; c = 0;
Δ = b2-4ac
Δ = -202-4·9·0
Δ = 400
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{400}=20$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-20)-20}{2*9}=\frac{0}{18}
=0
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-20)+20}{2*9}=\frac{40}{18}
=2+2/9
$