-30x+3x^2-66=-99+6x

Solution for -30x+3x^2-66=-99+6x equation:

-30x+3x^2-66=-99+6x

We move all terms to the left:

-30x+3x^2-66-(-99+6x)=0

We add all the numbers together, and all the variables

3x^2-30x-(6x-99)-66=0

We get rid of parentheses

3x^2-30x-6x+99-66=0

We add all the numbers together, and all the variables

3x^2-36x+33=0

a = 3; b = -36; c = +33;
Δ = b2-4ac
Δ = -362-4·3·33
Δ = 900
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{900}=30$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-36)-30}{2*3}=\frac{6}{6}
=1
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-36)+30}{2*3}=\frac{66}{6}
=11
$