2=square root of 22-8x

2  =  √( 22 - 8x )

To get rid of the square root, square both sides:

( 2 )²  =  [ √( 22 - 8x ) ]²

Squaring removes the square root:

4  =  22 - 8x

Subtract 22 from both sides:

-18  =  - 8x

Divide by -8:

x = -18 / -8  =  9/4