Solve x2 + 6x = 7 by completing the square. which is the solution set of the equation?

For the answer to the question above, from the equation  x^2 - 6x + 7 = 0 , b is equal to -6. The form should become y = (x-(b/2)^2) + c. (b/2)^2 is equal to 9. Hence,

0 = (x - 3)^2 -9 + 7 
0 = (x - 3)^2 -2
2 = (x - 3)^2

x should be equal to -1.5858 and -4.4142
I hope this helps