Answer:
12
Step-by-step explanation:
3/4 can be written as 9/12, I did this by multiplying both the denominator and numerator by 3.
1/3 can be written as 4/12, I did this by multiplying both the denominator and numerator by 4.
And we don't need to change 7/12 because that is already in the denominator of 12.
