Answer:
i think it is 9/28 but i am not shure
Explanation:
i found the lcd (least comon denominator) and made
28/4 and 28/1 and the multiplyed the number i multipyed to the denominator to the top number and got 28/16 and 28/7 and then subtracted that
i am not shure that that is correct tho
srry if wrong (:(