195-9x(21x+3)=128*12x

Solution for 195-9x(21x+3)=128*12x equation:

195-9x(21x+3)=128*12x

We move all terms to the left:

195-9x(21x+3)-(128*12x)=0

We add all the numbers together, and all the variables

-9x(21x+3)-(+128*12x)+195=0

We multiply parentheses

-189x^2-27x-(+128*12x)+195=0

We get rid of parentheses

-189x^2-27x-128*12x+195=0

Wy multiply elements

-189x^2-27x-1536x+195=0

We add all the numbers together, and all the variables

-189x^2-1563x+195=0

a = -189; b = -1563; c = +195;
Δ = b2-4ac
Δ = -15632-4·(-189)·195
Δ = 2590389
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{2590389}=\sqrt{9*287821}=\sqrt{9}*\sqrt{287821}=3\sqrt{287821}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-1563)-3\sqrt{287821}}{2*-189}=\frac{1563-3\sqrt{287821}}{-378}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-1563)+3\sqrt{287821}}{2*-189}=\frac{1563+3\sqrt{287821}}{-378}
$