50=(x-25)(x-15)

Solution for 50=(x-25)(x-15) equation:

50=(x-25)(x-15)

We move all terms to the left:

50-((x-25)(x-15))=0

We multiply parentheses ..

-((+x^2-15x-25x+375))+50=0


We calculate terms in parentheses: -((+x^2-15x-25x+375)), so:

(+x^2-15x-25x+375)

We get rid of parentheses

x^2-15x-25x+375

We add all the numbers together, and all the variables

x^2-40x+375

Back to the equation:

-(x^2-40x+375)


We get rid of parentheses

-x^2+40x-375+50=0

We add all the numbers together, and all the variables

-1x^2+40x-325=0

a = -1; b = 40; c = -325;
Δ = b2-4ac
Δ = 402-4·(-1)·(-325)
Δ = 300
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{300}=\sqrt{100*3}=\sqrt{100}*\sqrt{3}=10\sqrt{3}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(40)-10\sqrt{3}}{2*-1}=\frac{-40-10\sqrt{3}}{-2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(40)+10\sqrt{3}}{2*-1}=\frac{-40+10\sqrt{3}}{-2}
$