Answer: D
Step-by-step explanation:
First, you have to multiply 2 by 7, because m=7. Then you have to multiply7 by -1 because n=-1. So on the top, you will get 14- -7. Now on the bottom, its just 7 + -1, which is 6. When there is a minus sign and a negative sign next to each other, for example 14- -7, you have to add. Next, you had 14 and 7 to get 21. Finally, you have to divide 21/6 and you get 3.5, which as a fraction is 7/2.
hope this helps :)