Answer:

Step-by-step explanation:
First we need to find a common denominator between 7y, 8y, and 6y. And the smallest common denominator is 336y, which I got by multiplying 7*8*6 and since they all share y, we can just keep the y without multiplying it.
Now, we need to multiply each fraction by the correct number on the top and bottom to reach 336. When we do this, we get
. OMG. Well, now we need to expand the numerators...
. Another OMG. But now we need to simplify...so we get
. Done.
Hope this helps! :)