3/4 and 1/3
4x3 = 12 that will be the common denominator.
For 3/4 we first divide 12/4 = 3 and then multiply 3 x3 = 9 that's the numerator
For 1/3 we first divide 12/3 = 4 and then multiply 1x4 = 4 that's the numerator
The fractions will be rewrited as: 9/12 and 4/12