To preserve the value of a rational expression it is necessary to do the denominator just what you did to the numerator.
You see, nothing changes.
To 'clear' the denominator of a rational equation, it is necessary to multiply each term by the LCD. As long as you are multipling both sides of the equation by the same thing, nothing changes.
The LCD is 28(x+2)
Multiply each side by 28(x+2)