R2+2r-33=0 solve by completing the square

R^2+2r-33=0  move constant to other side by adding 33 to both sides

r^2+2r=33   halve the linear coefficient, square it and add to both sides, in this case it is just one

r^2+2r+1=34  now the left side is a perfect square...

(r+1)^2=34  take the square root of both sides...

r+1=34^(1/2)  subtract 1 from both sides

r=-1+34^(1/2) and -1-34^(1/2)