(8+2x)(28+2x)=924

Solution for (8+2x)(28+2x)=924 equation:

(8+2x)(28+2x)=924

We move all terms to the left:

(8+2x)(28+2x)-(924)=0

We add all the numbers together, and all the variables

(2x+8)(2x+28)-924=0

We multiply parentheses ..

(+4x^2+56x+16x+224)-924=0

We get rid of parentheses

4x^2+56x+16x+224-924=0

We add all the numbers together, and all the variables

4x^2+72x-700=0

a = 4; b = 72; c = -700;
Δ = b2-4ac
Δ = 722-4·4·(-700)
Δ = 16384
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{16384}=128$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(72)-128}{2*4}=\frac{-200}{8}
=-25
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(72)+128}{2*4}=\frac{56}{8}
=7
$