(30-2x)(18-2x)=448

Solution for (30-2x)(18-2x)=448 equation:

(30-2x)(18-2x)=448

We move all terms to the left:

(30-2x)(18-2x)-(448)=0

We add all the numbers together, and all the variables

(-2x+30)(-2x+18)-448=0

We multiply parentheses ..

(+4x^2-36x-60x+540)-448=0

We get rid of parentheses

4x^2-36x-60x+540-448=0

We add all the numbers together, and all the variables

4x^2-96x+92=0

a = 4; b = -96; c = +92;
Δ = b2-4ac
Δ = -962-4·4·92
Δ = 7744
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{7744}=88$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-96)-88}{2*4}=\frac{8}{8}
=1
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-96)+88}{2*4}=\frac{184}{8}
=23
$