Question 227879
Ok, for the first part, 3y-15 over 14 / y-5 over 4y.
Once you have those equations set up, after you do the reciprocal.. it should be 4y over y-5. 
{{{(3y-15)/(14)}}}x{{{(4y)/(y-5)}}}          
                       

Next step, 3y-15, you can simplify that more by finding the lowest common factor between the two numbers. In this case, it's 3 because it can go into 15 and into itself.
So now, your problem would look like this:

{{{3(y-5)/(14)}}}x {{{(4y)/(y-5)}}}

Looking at the problem now, we can simplify by crossing out the y-5 from both the top and bottom of the fractions. 
Here's what it would look like next:
{{{(3)*cross(y-5)/(14)}}}x{{{(4y)/cross(y-5)}}}


Here's the next step if you're stuck from this point:

{{{(12y)/(14)}}}         

You would multiply 3x4y to equal 12 which is still over 14.  Simplify further by finding a common factor between the two numbers. Common factor would be 2, the answer = {{{6y/7}}}
Now, for the next part:

{{{(81a^2)/2(a-3)}}}x{{{(2a-6)/(a-3)}}}
     
Here, it's one of the same steps as before. Simplify by taking (2a-6) and finding the lowest common factor. In this equation, 2 is the only option because it can go into 6, and itself.
 
This is what the step would look like:

{{{(81a^2)/2(a-3)}}}x{{{2(a-3)/(a-3)}}}

Here, you can see that you can simplify further by crossing out the 2(a-3) from the top and the bottom.
This is what the step would look like:

{{{(81a^2)/(a-3)}}}     


Now, you can't simplify any further.


The last equation you were asking about, the answer is x-91 because you can't do anything with it, in all of the steps in the problem after simplifying everything, you're left with x-91.