(30-2x)(18-2x)=160

Solution for (30-2x)(18-2x)=160 equation:

(30-2x)(18-2x)=160

We move all terms to the left:

(30-2x)(18-2x)-(160)=0

We add all the numbers together, and all the variables

(-2x+30)(-2x+18)-160=0

We multiply parentheses ..

(+4x^2-36x-60x+540)-160=0

We get rid of parentheses

4x^2-36x-60x+540-160=0

We add all the numbers together, and all the variables

4x^2-96x+380=0

a = 4; b = -96; c = +380;
Δ = b2-4ac
Δ = -962-4·4·380
Δ = 3136
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{3136}=56$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-96)-56}{2*4}=\frac{40}{8}
=5
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-96)+56}{2*4}=\frac{152}{8}
=19
$