(14-2x)(18-2x)=140

Solution for (14-2x)(18-2x)=140 equation:

(14-2x)(18-2x)=140

We move all terms to the left:

(14-2x)(18-2x)-(140)=0

We add all the numbers together, and all the variables

(-2x+14)(-2x+18)-140=0

We multiply parentheses ..

(+4x^2-36x-28x+252)-140=0

We get rid of parentheses

4x^2-36x-28x+252-140=0

We add all the numbers together, and all the variables

4x^2-64x+112=0

a = 4; b = -64; c = +112;
Δ = b2-4ac
Δ = -642-4·4·112
Δ = 2304
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{2304}=48$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-64)-48}{2*4}=\frac{16}{8}
=2
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-64)+48}{2*4}=\frac{112}{8}
=14
$