How do you factor the polynomials rp-9r+9p-81?

1 Answer
JJ
Aug 20, 2017

(r+9)(p-9)

Explanation:

To factor, you need to find like terms. The like terms in this expression are 9, p, and r. If you notice how the expression is written, you see that r is a common in the first two terms. 9 is common in the second two terms. Let's factor out r from the first two terms and 9 from the second two terms.

rp-9r+9p-81 ->

r(p-9)+9(p-9)

Now we have (p-9) as the common term. We can factor out (p-9) to get the factored form of the whole expression.

r(p-9)+9(p-9) ->

(p-9)(r+9) OR (r+9)(p-9)

If you want to check your answer, you can FOIL it or plug in two random numbers for r and p.

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