Answer:Alright, so I'm guessing that you need help on questions 7), 8), 9), 10), and so on. Step-by-step explanation:Please read the explanation in order to be able to answer the questions on your own (since you have to know how the concept works and figure out problems like these on tests or quizzes. ^^)7) 5/8-2/5LCM (Least Common Multiple): If you want one way, you can simply multiply the denominators (5 and 8). 5*8=40. So, LCM: 40.5/8=5*5/8*5 (since 8 times 5 is 40, so we also have to multiply the numerator), which equals to 25/40. Same thing goes to the other number, 2/5. 2/5=2*8/5*8 (since 5 times 8 is 40 and we need the same denominators for both fractions), which equals to 16/40.Lastly, this is the very simple step. Subtract both numbers in order to find the answer. 25/40-16/40=9/40. If needed to, simplify the fraction (since all fractions must be simplified.)Now, let's do one more problem and see if you understand the concept. 8) 16/5-2 1/2=16/5-5/2LCM: 1016*2/5*2=32/105*5/2*5=25/1032/10-25/10=7/10.