I'll assume it's 



Since there is a fraction on the left side, make the
right side a fraction too by putting a 1 under it:



What you want is w or 1w, not .

So you have to multply  by its reciprocal 
to make  into 1.

But if you multiply one side by  you have to
multiply the other side by  too.



Cancel the 9's on the left:



Cancel the 7's on the left AND the right:



Now all that's left is



Edwin