Remark
I don't think you are intended to use algebra. If you are, leave a note and one of us will get back to you.
I think the best way to tackle this problem is to start with the sum. And then look at the difference.
Solve
What does the sum tell you? It tells you that there are two whole numbers that add to 41. Let's take two extremes.
Solution 1
Take two numbers that are close together. 20 and 21 are very close together. They add to 41. Their difference is 1
Now take 2 numbers that are far apart like 40 and 1. That gives a difference of 39. Which result is closes to the difference of 25? The bottom one is a little closer to a difference of 25. So work from that. Make a table
Largest Number Second Number Sum Difference
39 2 41 37
37 4 41 33
35 6 41 29
34 7 41 27
33 8 41 25
The two numbers that resolve the problem are 33 and 8 which has a difference of 25.
The last line is your answer. 33 and 8 <<<< Answer