3x(x+4)=2x-7

Solution for 3x(x+4)=2x-7 equation:

3x(x+4)=2x-7

We move all terms to the left:

3x(x+4)-(2x-7)=0

We multiply parentheses

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

We get rid of parentheses

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

We add all the numbers together, and all the variables

3x^2+10x+7=0

a = 3; b = 10; c = +7;
Δ = b2-4ac
Δ = 102-4·3·7
Δ = 16
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{16}=4$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(10)-4}{2*3}=\frac{-14}{6}
=-2+1/3
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(10)+4}{2*3}=\frac{-6}{6}
=-1
$