Given:
I: My age.
S: My son.
G: My grandson.
If you add all our ages together, the sum is
100 years.
SOLVING:I + S + G = 100
===> First equation.S = 7G
===> Second equation.I = 12G
===> Third equation.We replace the
second equation and the
third ecuation in the
first equation:
12G + 7G + G = 100
20G = 100
G =

G = 5
years old.
===> My grandson.S = 7(5)
S = 35 years old.
===> My son.I = 12(5)
I = 60 years old.
===> My age. SOLUTION
TESTING:
GOOD LUCK...!!!