(55-x)(40-x)=2200

Solution for (55-x)(40-x)=2200 equation:

(55-x)(40-x)=2200

We move all terms to the left:

(55-x)(40-x)-(2200)=0

We add all the numbers together, and all the variables

(-1x+55)(-1x+40)-2200=0

We multiply parentheses ..

(+x^2-40x-55x+2200)-2200=0

We get rid of parentheses

x^2-40x-55x+2200-2200=0

We add all the numbers together, and all the variables

x^2-95x=0

a = 1; b = -95; c = 0;
Δ = b2-4ac
Δ = -952-4·1·0
Δ = 9025
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{9025}=95$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-95)-95}{2*1}=\frac{0}{2}
=0
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-95)+95}{2*1}=\frac{190}{2}
=95
$