Write an equation which models how old in years each of you will be when you are three times as old as the younger person. My age is 30, my son is 6.

2 answers

30+x=3(6+x)
first observe that you are 24 years older than your son. also, since we are required of the ages, we represent these unknown ages using variables:
let x = your son's age
let x+24 = your age
note that when your son's age is x years, you are three times as old. therefore,
3x = x+24
3x-x = 24
2x = 24
x = 12 years old (age of your son)
and your age is
x+24 = 36 years old

checking: note that 12*3 = 36, which satisfies the condition given.

hope this helps~ :)