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

1 Answer
Aug 20, 2017

Answer:

#(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.