0=x^2-30x+50

Solution for 0=x^2-30x+50 equation:

0=x^2-30x+50

We move all terms to the left:

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

We add all the numbers together, and all the variables

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

We get rid of parentheses

-x^2+30x-50=0

We add all the numbers together, and all the variables

-1x^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}
$