2x(x-5)=50

Solution for 2x(x-5)=50 equation:

2x(x-5)=50

We move all terms to the left:

2x(x-5)-(50)=0

We multiply parentheses

2x^2-10x-50=0

a = 2; b = -10; c = -50;
Δ = b2-4ac
Δ = -102-4·2·(-50)
Δ = 500
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:

$\sqrt{\Delta}=\sqrt{500}=\sqrt{100*5}=\sqrt{100}*\sqrt{5}=10\sqrt{5}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-10)-10\sqrt{5}}{2*2}=\frac{10-10\sqrt{5}}{4}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-10)+10\sqrt{5}}{2*2}=\frac{10+10\sqrt{5}}{4}
$