Factor pairs of 9 are any two numbers that, when multiplied together, equal 9. The question to ask is “what two numbers multiplied together equal 9?” Every factor can be paired with another factor, and multiplying the two will result in 9.
To find the factor pairs of 9, follow these steps:
Step 1:
Find the smallest prime number that is larger than 1, and is a factor of 9. For reference, the first prime numbers to check are 2, 3, 5, 7, 11, and 13. In this case, the smallest factor that’s a prime number larger than 1 is 3.
Step 2:
Divide 9 by the smallest prime factor, in this case, 3:
9 ÷ 3 = 3
3 and 3 will make a new factor pair.
Step 3:
Repeat Steps 1 and 2, using 3 as the new focus. Find the smallest prime factor that isn’t 1, and divide 3 by that number. In this case, 3 is the new smallest prime factor:
3 ÷ 3 = 1
Remember that this new factor pair is only for the factors of 3, not 9. So, to finish the factor pair for 9, you’d multiply 3 and 3 before pairing with 1:
3 x 3 = 9
Step 4:
Repeat this process until there are no longer any prime factors larger than one to divide by. At the end, you should have the full list of factor pairs.
Here are all the factor pairs for 9:
(1, 9), (3, 3)
So, to list all the factors of 9: 1, 3, 9
The negative factors of 9 would be: -1, -3, -9