No, the two sides of the equation are separate.
If you need to add 8 it should be clearly shown that 8 is added to BOTH sides, and EACH side is then simplified independently of the the other.
Grouping part of an equation together does not make any sense.
In this form, where would the +8 be used? Does this imply solve the equation and then add 8 afterwards? Then the solution would no longer be correct.