-30=x^2-11x

Solution for -30=x^2-11x equation:

-30=x^2-11x

We move all terms to the left:

-30-(x^2-11x)=0

We get rid of parentheses

-x^2+11x-30=0

We add all the numbers together, and all the variables

-1x^2+11x-30=0

a = -1; b = 11; c = -30;
Δ = b2-4ac
Δ = 112-4·(-1)·(-30)
Δ = 1
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1}=1$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(11)-1}{2*-1}=\frac{-12}{-2}
=+6
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(11)+1}{2*-1}=\frac{-10}{-2}
=+5
$