(50-2x)(40-2x)=875

Solution for (50-2x)(40-2x)=875 equation:

(50-2x)(40-2x)=875

We move all terms to the left:

(50-2x)(40-2x)-(875)=0

We add all the numbers together, and all the variables

(-2x+50)(-2x+40)-875=0

We multiply parentheses ..

(+4x^2-80x-100x+2000)-875=0

We get rid of parentheses

4x^2-80x-100x+2000-875=0

We add all the numbers together, and all the variables

4x^2-180x+1125=0

a = 4; b = -180; c = +1125;
Δ = b2-4ac
Δ = -1802-4·4·1125
Δ = 14400
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{14400}=120$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-180)-120}{2*4}=\frac{60}{8}
=7+1/2
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-180)+120}{2*4}=\frac{300}{8}
=37+1/2
$