(2x+2)x+2=40

Solution for (2x+2)x+2=40 equation:

(2x+2)x+2=40

We move all terms to the left:

(2x+2)x+2-(40)=0

We add all the numbers together, and all the variables

(2x+2)x-38=0

We multiply parentheses

2x^2+2x-38=0

a = 2; b = 2; c = -38;
Δ = b2-4ac
Δ = 22-4·2·(-38)
Δ = 308
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:

$\sqrt{\Delta}=\sqrt{308}=\sqrt{4*77}=\sqrt{4}*\sqrt{77}=2\sqrt{77}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(2)-2\sqrt{77}}{2*2}=\frac{-2-2\sqrt{77}}{4}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(2)+2\sqrt{77}}{2*2}=\frac{-2+2\sqrt{77}}{4}
$