These problems they are very har

To rewrite it in exponent for keep the number that is being repeated for the bottom and count how many times the number shows up as the exponent. 
Answer for first one section B:20^6
Answer for fist one section A:6x6x6x6x6x6x6x6

The numbers in the exponents just define how many times you have to multiply the same number by itself. Thus

A
1. 6^8 is the same as:
  6*6*6*6*6*6*6*6 ...which equals 1679616

2. 8^7 is the same as:
  8*8*8*8*8*8*8 which equals 2097152

B
1. 20*20*20*20*20*20 is equivalent to: 20^6
2. 14*14*14*14*14 is equivalent to: 14^5