luis is six years younger than santiago. Michael is three times as old as santiago. The sum of their ages is 59.How old is Michael?

Michael is 39 years old.

Step-by-step explanation:

Let l stand for Luis, s stand for Santiago, and m stand for Michael.

l = s - 6

m = 3s

s + (s-6) + 3s = 59

s + s - 6 + 3s = 59

5s - 6 = 59

     +6     +6

5s = 65

/5     /5

s = 13

Now plug s into the equation that represents Michael:

m = 3s

m = 3(13)

m = 39

Michael is 39 years old.