-3(x-1+8)x-3=6x+7-5x

Solution for -3(x-1+8)x-3=6x+7-5x equation:

-3(x-1+8)x-3=6x+7-5x

We move all terms to the left:

-3(x-1+8)x-3-(6x+7-5x)=0

We add all the numbers together, and all the variables

-3(x+7)x-(x+7)-3=0

We multiply parentheses

-3x^2-21x-(x+7)-3=0

We get rid of parentheses

-3x^2-21x-x-7-3=0

We add all the numbers together, and all the variables

-3x^2-22x-10=0

a = -3; b = -22; c = -10;
Δ = b2-4ac
Δ = -222-4·(-3)·(-10)
Δ = 364
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:

$\sqrt{\Delta}=\sqrt{364}=\sqrt{4*91}=\sqrt{4}*\sqrt{91}=2\sqrt{91}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-22)-2\sqrt{91}}{2*-3}=\frac{22-2\sqrt{91}}{-6}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-22)+2\sqrt{91}}{2*-3}=\frac{22+2\sqrt{91}}{-6}
$