3x(x+4)=2x-5

Solution for 3x(x+4)=2x-5 equation:

3x(x+4)=2x-5

We move all terms to the left:

3x(x+4)-(2x-5)=0

We multiply parentheses

3x^2+12x-(2x-5)=0

We get rid of parentheses

3x^2+12x-2x+5=0

We add all the numbers together, and all the variables

3x^2+10x+5=0

a = 3; b = 10; c = +5;
Δ = b2-4ac
Δ = 102-4·3·5
Δ = 40
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{40}=\sqrt{4*10}=\sqrt{4}*\sqrt{10}=2\sqrt{10}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(10)-2\sqrt{10}}{2*3}=\frac{-10-2\sqrt{10}}{6}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(10)+2\sqrt{10}}{2*3}=\frac{-10+2\sqrt{10}}{6}
$