For this you need to subtract 3 4\5 and 3 1\2. To solve these problems I personally used common denominators. Find least common factor which is 1. Think 1 times what is 5 the answer is 5. Now think 1 times 2 is what, the answer is 2. Now the common denominator will still be 2. Now do 5 time your numerator which is 20 which makes 20\1 and 2 time 1 which is 2 which make 2 over 1. So 20\1 minus 2\1 is 18\1. Then 3 minus 3. SO THE FINAL ANSWER IS 18\1.