Best ways of how to find common denominators

Fastest way is to multiply by each other’s denominators. Ie

1/3. And 5/6.

Multiply 1/3 * 6/6. This gives you 6/18 which is = 1/3

6/6 comes from the denominator of the other fraction

Then use the 3 to multiply for 5/6. 3/3 * 5/6 = 15/18 which does = 5/6

3/3 comes from denominator of the other fraction

So now we have common denominators. (18)

You always multiply the top and bottom by same number. Like 3/3. Because it’s = 1.

Igot the answer of 15.8 years.