r^2-8r=33

Solution for r^2-8r=33 equation:

r^2-8r=33

We move all terms to the left:

r^2-8r-(33)=0

a = 1; b = -8; c = -33;
Δ = b2-4ac
Δ = -82-4·1·(-33)
Δ = 196
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$r_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$r_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{196}=14$
$r_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-8)-14}{2*1}=\frac{-6}{2}
=-3
$
$r_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-8)+14}{2*1}=\frac{22}{2}
=11
$