What is 34/42 in simplest form

17/21 is the answer.My answer is 17/21 because when you simplify you are looking for a common number they are both divisible by and if you know common math then you would notice that both numbers are even which means they can be divided by 2 and you will come up with your answer.PS not all fractions can be simplified by two and sometimes they can't be simplifyed at all.EX: if I started with 17/21 then I could not simplify it anymore.