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

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

2x(x+2)+2(x-1)=4.2

We move all terms to the left:

2x(x+2)+2(x-1)-(4.2)=0

We add all the numbers together, and all the variables

2x(x+2)+2(x-1)-4.2=0

We multiply parentheses

2x^2+4x+2x-2-4.2=0

We add all the numbers together, and all the variables

2x^2+6x-6.2=0

a = 2; b = 6; c = -6.2;
Δ = b2-4ac
Δ = 62-4·2·(-6.2)
Δ = 85.6
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(6)-\sqrt{85.6}}{2*2}=\frac{-6-\sqrt{85.6}}{4}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(6)+\sqrt{85.6}}{2*2}=\frac{-6+\sqrt{85.6}}{4}
$