50=30x-x2

Solution for 50=30x-x2 equation:

50=30x-x2

We move all terms to the left:

50-(30x-x2)=0

We add all the numbers together, and all the variables

-(+30x-1x^2)+50=0

We get rid of parentheses

1x^2-30x+50=0

We add all the numbers together, and all the variables

x^2-30x+50=0

a = 1; b = -30; c = +50;
Δ = b2-4ac
Δ = -302-4·1·50
Δ = 700
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:

$\sqrt{\Delta}=\sqrt{700}=\sqrt{100*7}=\sqrt{100}*\sqrt{7}=10\sqrt{7}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-30)-10\sqrt{7}}{2*1}=\frac{30-10\sqrt{7}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-30)+10\sqrt{7}}{2*1}=\frac{30+10\sqrt{7}}{2}
$