(20-2x)(10-2x)=144

Solution for (20-2x)(10-2x)=144 equation:

(20-2x)(10-2x)=144

We move all terms to the left:

(20-2x)(10-2x)-(144)=0

We add all the numbers together, and all the variables

(-2x+20)(-2x+10)-144=0

We multiply parentheses ..

(+4x^2-20x-40x+200)-144=0

We get rid of parentheses

4x^2-20x-40x+200-144=0

We add all the numbers together, and all the variables

4x^2-60x+56=0

a = 4; b = -60; c = +56;
Δ = b2-4ac
Δ = -602-4·4·56
Δ = 2704
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{2704}=52$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-60)-52}{2*4}=\frac{8}{8}
=1
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-60)+52}{2*4}=\frac{112}{8}
=14
$