Answer :

Sure! Let's solve the problem step by step.

### Step-by-Step Solution:

1. List the given digits:
The digits provided are: 3, 5, 7, 2, 4, 8, 1, 9.

2. Find the smallest 8-digit number:
To form the smallest number, we need to arrange these digits in ascending order:
- Arrange in ascending order: 1, 2, 3, 4, 5, 7, 8, 9.
- Combine these sorted digits to form the smallest number: 12345789.

3. Find the greatest 8-digit number:
To form the greatest number, we need to arrange these digits in descending order:
- Arrange in descending order: 9, 8, 7, 5, 4, 3, 2, 1.
- Combine these sorted digits to form the greatest number: 98754321.

4. Conclusion:
- The smallest 8-digit number using all the given digits is 12345789.
- The greatest 8-digit number using all the given digits is 98754321.

Thus, the smallest and greatest 8-digit numbers that can be formed from the digits 3, 5, 7, 2, 4, 8, 1, 9 are 12345789 and 98754321, respectively.