I solved the equation below and got an answer of 9+-sqrt(57) but i don;t belive this is correct. help please.

5-sqrt(8x+1)=x
8x+1=x^2-10x+25
0=x^2-10x+25-8x-1
0=x^2-18x+24
then i completed the sqare
got 9+-sqrt(57)

THANKS SO MUCH