Question

The sum of two numbers is 21. Their product is 108. What are the two numbers?

Answer 1

9 and 21

Explanation:

First we can write the factors of 108:

1,108

2,54

3,36

4,27

6,18

9,12 - these 2 numbers add up to 21 so these 2 numbers is our answer.

Answer 2

12 and 9

• First, divide 108 by a relatively low number, 12

`108 / 12 = 9`

• Now that we have 9, multiply 9 by 12

`9 * 12 = 108`

• This is one method that proves the statement true. I call the method mirroring. This method consists of finding the lowest numbers a large number is divisible by, then flipping the problem to a multiplication problem.

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What have we learned?

We learned alternative ways to find the sum and product of a number using a similar method.

Questions related to the topic? Ask me in the comments box.