X=-3x(x+4)

Solution for X=-3x(x+4) equation:

X=-3X(X+4)

We move all terms to the left:

X-(-3X(X+4))=0


We calculate terms in parentheses: -(-3X(X+4)), so:

-3X(X+4)

We multiply parentheses

-3X^2-12X

Back to the equation:

-(-3X^2-12X)


We get rid of parentheses

3X^2+12X+X=0

We add all the numbers together, and all the variables

3X^2+13X=0

a = 3; b = 13; c = 0;
Δ = b2-4ac
Δ = 132-4·3·0
Δ = 169
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{169}=13$
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(13)-13}{2*3}=\frac{-26}{6}
=-4+1/3
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(13)+13}{2*3}=\frac{0}{6}
=0
$