Answer:
1st box(the top one in the middle row): 5^4-5 = 5^-1
2nd box(the top one in the last row): 5*5*5*5/5*5*5*5*5 = 1/5
3rd box(the bottom one in the middle row): x^-6
4th box(the bottom one in the last row): x/x*x*x*x*x*x*x=1/x^6
