Answer :

4 and 3 are Denominators so we have to find the GCF of 4 and 3. The GCF of 4 and 3 is 12, so our common Denominator will be 12. [tex] \frac{1*3}{4*3}=\boxed{ \frac{3}{12}} \ and \ \frac{2*4}{3*4}=\boxed{ \frac{8}{12}} [/tex]
So 1/4 & 2/3 would transform into 3/12 & 8/12