find two numbers which l.c.m is 12 and sum 10
Answers
First of all, you start by finding the prime numbers that you would need to get to 12. That would be 2x2x3. As you would be looking for two numbers, you would basically be limited to the numbers 2, 3, 4 (2x2) and 6 (2x3) as possible options.
Next, you know that they add up to 10 so you’ll see 4 and 6 in this set so that’s the answer. You basically do this by just taking every number from the list 2, 3, 4, 6 and subtract them from 10 to see if the result is another number from this list. 10–2 equals 8 so no. 10–3 equals 7 so no. 10–4 equals 6, Bingo!
When dealing with LCM start by factoring the number into prime numbers. Don’t add 1 to this list in this case, though. You have an infinite number of 1’s as part of the LCM so you have to skip it.
There are some tricks that can help optimize finding the result, but you’ll learn them when you become more advanced with math.