7x-(3x^2-12x)=0

Solution for 7x-(3x^2-12x)=0 equation:

7x-(3x^2-12x)=0

We get rid of parentheses

-3x^2+7x+12x=0

We add all the numbers together, and all the variables

-3x^2+19x=0

a = -3; b = 19; c = 0;
Δ = b2-4ac
Δ = 192-4·(-3)·0
Δ = 361
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{361}=19$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(19)-19}{2*-3}=\frac{-38}{-6}
=6+1/3
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(19)+19}{2*-3}=\frac{0}{-6}
=0
$