Factor pairs of 84 are any two numbers that, when multiplied together, equal 84. The question to ask is “what two numbers multiplied together equal 84?” Every factor can be paired with another factor, and multiplying the two will result in 84.
To find the factor pairs of 84, follow these steps:
Step 1:
Find the smallest prime number that is larger than 1, and is a factor of 84. 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 2.
Step 2:
Divide 84 by the smallest prime factor, in this case, 2:
84 ÷ 2 = 42
2 and 42 will make a new factor pair.
Step 3:
Repeat Steps 1 and 2, using 42 as the new focus. Find the smallest prime factor that isn’t 1, and divide 42 by that number. In this case, 2 is the new smallest prime factor:
42 ÷ 2 = 21
Remember that this new factor pair is only for the factors of 42, not 84. So, to finish the factor pair for 84, you’d multiply 2 and 2 before pairing with 21:
2 x 2 = 4
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 84:
(1, 84), (2, 42), (3, 28), (4, 21), (6, 14), (7, 12)
So, to list all the factors of 84: 1, 2, 3, 4, 6, 7, 12, 14, 21, 28, 42, 84
The negative factors of 84 would be: -1, -2, -3, -4, -6, -7, -12, -14, -21, -28, -42, -84