how to subtract mixed numbers?

4* 1/4 - 2* 2/3 = now i need to change it to improper fraction.

17/4 - 7/3= change IT to LCM.

51/12- 28/12= 22/ 12 NOW THAT I HAVE THE ANSWER CHANGE IT TO MIXED AGAIN.

22/12= 1* 10/12