Simplify :
4a(6) + 3a

1. 24 a2 + 3 a
2. 13 a
3. 27 a
4. 27 a2

Suppose you are choosing a 6-digit personal access code. this code is made up of 4 digits chosen from 1 to 9, followed by 2 letters chosen from a to z. any of these digits or letters can be repeated. find the total number of personal access codes that can be formed. 492,804 341,172 39,917,124 4,435,236