The sum of two integers is 54 and their difference is 24

Step-by-step explanation:

x + y = 54

x - y = 24

Adding the equations, we find:

2x = 78

x = 78/2 = 39

Replacing x by 39 in the first equation, comes: 39 + y = 54

So, y = 54 - 39; y = 15

Therefore, the unknown numbers are 39 and 15.