Answer:
10000 options
Step-by-step explanation:
There are 10 options of digit from 0 to 9. It means there are 10 options for the first slot, 10 for the 2nd slot, 10 for the 3rd slot, and 10 for the last slot of each of the 4 slots of the password. For all 4 passwords the total amount of choices would be
To solve this absolute value equation, we can use find the solutions as follows taking into account the definition of absolute value, then, we have:
Now, we can solve both equations to find the solution(s):
First case:
Second case:
Then, both solutions are the same, because of the absolute rule (this is the point when y = 0, that is the x-intercept for this function.)
Therefore, the solution set is {19/20}.
