A=(6-2x)(8-2x)

Solution for A=(6-2x)(8-2x) equation:

=(6-2A)(8-2A)

We move all terms to the left:

-((6-2A)(8-2A))=0

We add all the numbers together, and all the variables

-((-2A+6)(-2A+8))=0

We multiply parentheses ..

-((+4A^2-16A-12A+48))=0


We calculate terms in parentheses: -((+4A^2-16A-12A+48)), so:

(+4A^2-16A-12A+48)

We get rid of parentheses

4A^2-16A-12A+48

We add all the numbers together, and all the variables

4A^2-28A+48

Back to the equation:

-(4A^2-28A+48)


We get rid of parentheses

-4A^2+28A-48=0

a = -4; b = 28; c = -48;
Δ = b2-4ac
Δ = 282-4·(-4)·(-48)
Δ = 16
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$A_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$A_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{16}=4$
$A_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(28)-4}{2*-4}=\frac{-32}{-8}
=+4
$
$A_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(28)+4}{2*-4}=\frac{-24}{-8}
=+3
$