The sum of two numbers is fifteen. the product of the two numbers is thirty six. find the numbers

Best to take this in two parts. 

1, find the factors of 36:
1 and 36
2 and 18
3 and 12
4 and 9
6 and 6

2, Now, using those, add the factors and see which add up to 15... in this case, that would be 12 and 3!

One way is to find the factors of 36
factors are
1,36
2,18
3,12
4,9
6,6
add them
1+36=37
2+18=20
3+12=15 match
4+9=13
6+6=12

the numbesr are 3 and 12

Where’s the