(3+2x)(5+2x)=15

Solution for (3+2x)(5+2x)=15 equation:

(3+2x)(5+2x)=15

We move all terms to the left:

(3+2x)(5+2x)-(15)=0

We add all the numbers together, and all the variables

(2x+3)(2x+5)-15=0

We multiply parentheses ..

(+4x^2+10x+6x+15)-15=0

We get rid of parentheses

4x^2+10x+6x+15-15=0

We add all the numbers together, and all the variables

4x^2+16x=0

a = 4; b = 16; c = 0;
Δ = b2-4ac
Δ = 162-4·4·0
Δ = 256
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{256}=16$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(16)-16}{2*4}=\frac{-32}{8}
=-4
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(16)+16}{2*4}=\frac{0}{8}
=0
$