Hey there!
First, let's list the factors of 40:
1 x 40, 2 x 20, 4 x 10, 5 x 8,
We need to figure out which pair of factors has a sum of 13.
1 + 40 = 41 --> Nope
2 + 20 = 22 --> Nope
4 + 10 = 14 --> Nope
5 + 8 = 13 --> Yes!
The two numbers that have a product of 40 and a sum of 13 are 5 and 8.
Hope this helps!