The first digit of the password can be any of the ten digits - 10 possibilities.
A digit cannot be repeated, so the second digit can be any digit except the one you chose for the first digit - 9 possibilities.
The third digit can be any digit except the digits you chose for the first and second digit - 8 possibilities.
Using the rule of product:

There are 720 passwords.
Answer:
schools and other services
yes because you would subtract -9 from both sides of the equation leaving you with x = -4
Answer:
3,1
Step-by-step explanation: