I’m assuming the information you’ve given is for a picture. However, the picture isn’t showing.
Answer:
Shane started the problem correctly
Step-by-step explanation:
We are given problem (-5) - (-1 3/4).
Mariah started the problem as (-5) + 1 - 3/4
Shane started the problem as (-5) + 1 + 3/4
We need to find who started the problem correctly.
The problem should be started by converting the mixed fraction into improper fraction i,e

Now we will solve bracket by multiplying -1 with term inside the bracket i.e


Let's compare both the procedures now:
Mariah:



Therefore, Mariah did not start the problem correctly.
Shane:



Therefore, Shane started the problem correctly.
The second one if im not wrong
There are 3 nickels because if you use the ratio 6 to 1 you multiply 6 by 3 to get 18 pennies and you do the same with the one and that’s how I got 3 nickels.