1125=(50-2x)(30-2x)

Solution for 1125=(50-2x)(30-2x) equation:

1125=(50-2x)(30-2x)

We move all terms to the left:

1125-((50-2x)(30-2x))=0

We add all the numbers together, and all the variables

-((-2x+50)(-2x+30))+1125=0

We multiply parentheses ..

-((+4x^2-60x-100x+1500))+1125=0


We calculate terms in parentheses: -((+4x^2-60x-100x+1500)), so:

(+4x^2-60x-100x+1500)

We get rid of parentheses

4x^2-60x-100x+1500

We add all the numbers together, and all the variables

4x^2-160x+1500

Back to the equation:

-(4x^2-160x+1500)


We get rid of parentheses

-4x^2+160x-1500+1125=0

We add all the numbers together, and all the variables

-4x^2+160x-375=0

a = -4; b = 160; c = -375;
Δ = b2-4ac
Δ = 1602-4·(-4)·(-375)
Δ = 19600
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{19600}=140$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(160)-140}{2*-4}=\frac{-300}{-8}
=37+1/2
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(160)+140}{2*-4}=\frac{-20}{-8}
=2+1/2
$