(2x+6)*(2x+3)=40

Solution for (2x+6)*(2x+3)=40 equation:

(2x+6)(2x+3)=40

We move all terms to the left:

(2x+6)(2x+3)-(40)=0

We multiply parentheses ..

(+4x^2+6x+12x+18)-40=0

We get rid of parentheses

4x^2+6x+12x+18-40=0

We add all the numbers together, and all the variables

4x^2+18x-22=0

a = 4; b = 18; c = -22;
Δ = b2-4ac
Δ = 182-4·4·(-22)
Δ = 676
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{676}=26$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(18)-26}{2*4}=\frac{-44}{8}
=-5+1/2
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(18)+26}{2*4}=\frac{8}{8}
=1
$