SOLUTION: Subtract and simplify: {{{2/(x+1)-3/(x-3)}}} please show all steps

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Question 69365: Subtract and simplify: 2%2F%28x%2B1%29-3%2F%28x-3%29 please show all steps
Answer by Edwin McCravy(20060) About Me  (Show Source):
You can put this solution on YOUR website!
2%2F%28x%2B1%29-3%2F%28x-3%29

The LCD is the product of the denominators %28x%2B1%29%28x-3%29:

We ask ourselves:

What factor does the denominator of the first fraction
2%2F%28x%2B1%29, which is %28x%2B1%29, lack which the LCD contains?

The answer is that it lacks the factor %28x-3%29. 

Therefore we multiply the first fraction by %28x-3%29%2F%28x-3%29
which:

(1) Does not change its value because %28x-3%29%2F%28x-3%29 equals
    1 and multiplying by 1 does not change any value.
(2) It will cause the denominator of the first fraction to be
    the LCD %28x%2B1%29%28x-3%29

So 2%2F%28x%2B1%29-3%2F%28x-3%29

becomes:

%282%2F%28x%2B1%29%29%28%28x-3%29%2F%28x-3%29%29-3%2F%28x-3%29

Now we do the same with the second fraction. We ask ourselves:

What factor does the denominator of the second fraction
-3%2F%28x-3%29, which is %28x-3%29, lack which the LCD contains?

The answer is that it lacks the factor %28x%2B1%29. 

Therefore we multiply the second fraction by %28x%2B1%29%2F%28x%2B1%29
which:

(1) Does not change its value because %28x%2B1%29%2F%28x%2B1%29 equals
    1 and multiplying by 1 does not change any value.
(2) It will cause the denominator of the second fraction to be
    the LCD %28x%2B1%29%28x-3%29

So  %282%2F%28x%2B1%29%29%28%28x-3%29%2F%28x-3%29%29-3%2F%28x-3%29

becomes

    

or

    

Now the denominators are the same, i.e., both denominators
are now equal to the LCD %28x%2B1%29%28x-3%29

Multiply the tops out but do not multiply out the bottoms:

    +%282x-6%29%2F%28%28x%2B1%29%28x-3%29%29+-+%283x%2B3%29%2F%28%28x-3%29%28x%2B1%29%29

Since the denominators are the same we indicate the
subtraction of the numerators over the LCD:

+%28%282x-6%29-%283x%2B3%29%29%2F%28%28x%2B1%29%28x-3%29%29

Remove the parentheses in the top but not in the bottom:

+%282x-6-3x-3%29%2F%28%28x%2B1%29%28x-3%29%29

Combine terms in the numerator:

+%28-x-9%29%2F%28%28x%2B1%29%28x-3%29%29

I am sure your teacher would accept that answer. But
if you like you can factor -1 out of the numerator:

+%28-1%29%28x%2B9%29%2F%28%28x%2B1%29%28x-3%29%29

and then eliminate the %28-1%29 by putting a negative 
sign out in front of the fraction:

+-%28x%2B9%29%2F%28%28x%2B1%29%28x-3%29%29
 
Edwin