There would be 100,000 if there are no restrictions on the digits and 90,000 if they cannot use 0 as the first digit.
If there are no restrictions, there are 10 possibilities for each digit:
10(10)(10)(10)(10) = 100,000
If the first digit cannot be 0, there are 9 possibilities for it and 10 possibilities for each of the other 4:
9(10)(10)(10)(10) = 90,000
a. Recall that

For
, we have

By integrating both sides, we get

If
, then

so that

We can shift the index to simplify the sum slightly.

b. The power series for
can be obtained simply by multiplying both sides of the series above by
.

c. We have


Answer: I thin it's A because you just multiply 19*6
Step-by-step explanation:
Answer: idk
Step-by-step explanation: how am i supposed to know