(2x+1)*(x+4)=4

Solution for (2x+1)*(x+4)=4 equation:

(2x+1)(x+4)=4

We move all terms to the left:

(2x+1)(x+4)-(4)=0

We multiply parentheses ..

(+2x^2+8x+x+4)-4=0

We get rid of parentheses

2x^2+8x+x+4-4=0

We add all the numbers together, and all the variables

2x^2+9x=0

a = 2; b = 9; c = 0;
Δ = b2-4ac
Δ = 92-4·2·0
Δ = 81
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{81}=9$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(9)-9}{2*2}=\frac{-18}{4}
=-4+1/2
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(9)+9}{2*2}=\frac{0}{4}
=0
$