Smallest positive integer to clear fractions

Question

2/3x-4/5=1-1/6x

Answer 1

The largest one you'd need to consider would be 3 * 5 * 6 -- multiplying all the denominators.

 

But can you use a smaller one?  Yes, because 6 is a multiple of 3, you know that using 30 (5 * 6) will take care of the 3 as well.

 

So multiplying both sides by 30 will clear all the fractions.