168-(14-2x)(12-2x)=69

Solution for 168-(14-2x)(12-2x)=69 equation:

168-(14-2x)(12-2x)=69

We move all terms to the left:

168-(14-2x)(12-2x)-(69)=0

We add all the numbers together, and all the variables

-(-2x+14)(-2x+12)+168-69=0

We add all the numbers together, and all the variables

-(-2x+14)(-2x+12)+99=0

We multiply parentheses ..

-(+4x^2-24x-28x+168)+99=0

We get rid of parentheses

-4x^2+24x+28x-168+99=0

We add all the numbers together, and all the variables

-4x^2+52x-69=0

a = -4; b = 52; c = -69;
Δ = b2-4ac
Δ = 522-4·(-4)·(-69)
Δ = 1600
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1600}=40$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(52)-40}{2*-4}=\frac{-92}{-8}
=11+1/2
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(52)+40}{2*-4}=\frac{-12}{-8}
=1+1/2
$