(X+4)(x-6)=3x

Solution for (X+4)(x-6)=3x equation:

(X+4)(X-6)=3X

We move all terms to the left:

(X+4)(X-6)-(3X)=0

We add all the numbers together, and all the variables

-3X+(X+4)(X-6)=0

We multiply parentheses ..

(+X^2-6X+4X-24)-3X=0

We get rid of parentheses

X^2-6X+4X-3X-24=0

We add all the numbers together, and all the variables

X^2-5X-24=0

a = 1; b = -5; c = -24;
Δ = b2-4ac
Δ = -52-4·1·(-24)
Δ = 121
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{121}=11$
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-5)-11}{2*1}=\frac{-6}{2}
=-3
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-5)+11}{2*1}=\frac{16}{2}
=8
$