The sum of two numbers is 39 . the smaller number is 13 less than the larger number. what are the numbers

13 and 26

13+26=39 and 26-13=13

38+105= 143, 39+104=143, and you will find then adding the numbers on opposite sides, moving inwards yields the answer 138 every time. because of this, you’re going to multiply 138 times the number of pairs, which is 34. therefore, 34*138= 4692(i’m sorry if it’s the wrong numbers, but it’s the right concept)