okay let's say I have 1/2 and 2/4 (this is really easy) so you take the multiples of the denominator and the numbers that are the same are known as common denominators so its
3 6 9 12 15 18 21 24
7 14 21 28
so that means 21 is the common denominator but there are way more than that trust me so now hopefully you guys get it
