Factor pairs of 126 are any two numbers that, when multiplied together, equal 126. The question to ask is “what two numbers multiplied together equal 126?” Every factor can be paired with another factor, and multiplying the two will result in 126.
To find the factor pairs of 126, follow these steps:
Step 1:
Find the smallest prime number that is larger than 1, and is a factor of 126. 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 126 by the smallest prime factor, in this case, 2:
126 ÷ 2 = 63
2 and 63 will make a new factor pair.
Step 3:
Repeat Steps 1 and 2, using 63 as the new focus. Find the smallest prime factor that isn’t 1, and divide 63 by that number. In this case, 3 is the new smallest prime factor:
63 ÷ 3 = 21
Remember that this new factor pair is only for the factors of 63, not 126. So, to finish the factor pair for 126, you’d multiply 2 and 3 before pairing with 21:
2 x 3 = 6
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 126:
(1, 126), (2, 63), (3, 42), (6, 21), (7, 18), (9, 14)
So, to list all the factors of 126: 1, 2, 3, 6, 7, 9, 14, 18, 21, 42, 63, 126
The negative factors of 126 would be: -1, -2, -3, -6, -7, -9, -14, -18, -21, -42, -63, -126