Multiply both the numerator and denominator by
, which is called the "conjugate" of
:

Why do we pick this number? Recall the difference of squares factorization:

Now replace
and
. Then

So in your fraction, you end up with

Finally, just expand the product.

Answer:
Via its graph, you can identify exponential and linear functions. Linear functions are straight lines, while curved lines are exponential functions. By the adjustment in y, you can also recognize them. If you apply the same number to y, then the function changes continuously and is linear.
Step-by-step explanation:
You would use, Order of Operations, A.K.A PEMDAS.
Parenthesis, Exponets, Multiplication, Division, Addition, Subtraction
Follow that order and you do the work yourself, you would never learn by asking other's for the answer. >:)
From: Dark Angel