Iwonder if i did #9 right and i’m having trouble with #10

9
It's correct. The only problem is entering it. Is a fraction OK or do you need to break it down to 16.6666

10
I don't wonder that you are having trouble with this.

Do it in parts. 
numerator
3/4 - 3/2 = 3/4 - 6/4 = - 3/4 Notice what happened. You multiplied top and bottom of 3/2 by 2
= 3*2 = 6
2 * 2 = 4

Now do the denominator
1/4 - 3/5 = 
5/20 - 12/20
= - 7/20

What do you have?
-3/4 // - 7/20 Now invert and multiply
- 3/4 * - 20 /7
= 60/ 28
= 15 / 7 Where did the two minus' go?