Answer:
39
Step-by-step explanation:
x-3y=9
x-y=29
subtract
-2y=-20
y=10
x-10=29
x=39
Answer:
7 digits can be used for each position
There are a total of 5 positions
N = 7^5 = 16,807 numbers
You have 7 choices for the first position, second position, etc.
Answer:
5
Step-by-step explanation:
= 5