Answer:
11. D
12. B?
13. A
14. C
15. E
Step-by-step explanation:
I'm not completely sure about 12
...
C
My Apologies if Wrong!
Step-by-step:
51⁷-51⁶ = 51⁶(51-1) = 51⁶(50)
50 is divisible by 25, so 51⁷-51⁶ is divisible by 25.
