(11-2x)(9-2x)=35

Solution for (11-2x)(9-2x)=35 equation:

(11-2x)(9-2x)=35

We move all terms to the left:

(11-2x)(9-2x)-(35)=0

We add all the numbers together, and all the variables

(-2x+11)(-2x+9)-35=0

We multiply parentheses ..

(+4x^2-18x-22x+99)-35=0

We get rid of parentheses

4x^2-18x-22x+99-35=0

We add all the numbers together, and all the variables

4x^2-40x+64=0

a = 4; b = -40; c = +64;
Δ = b2-4ac
Δ = -402-4·4·64
Δ = 576
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{576}=24$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-40)-24}{2*4}=\frac{16}{8}
=2
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-40)+24}{2*4}=\frac{64}{8}
=8
$