You can factor the two numbers using one common factor. Let us use common factor 2.
Given that 24/2 = 12 and 40/2 = 20, you can write: 24 + 40 = 2 (12 + 20).
The distributive property applied to 2 (12 + 20) is:
2* 12 + 2*20 = 24 + 40.
Remember that the rule for the distributive property is: (m+n)(x+y) = mx + my + nx + ny