First, you would have to make a common denominator. To do this, multiply these 2 denominator, 5 and 7. You should get 35. Then, you would have to make the numerator equal to the denominator. In this case, multiply 3 to 7 and 2 to 5. Now you have 21/35 and 10/35. Now subtract 21 from 10, and simplify if needed. I hope this helps!
