today, johns mom is 5 times as old as he is. in 7 years she will only be 3 times as old. what is johns age today?
X yrs. = John's age today.
5x yrs. = John's mom's age today.
7 years from now:
x+7 = John's age.
5x+7 = John's mom's age.
5x+7 = 3(x+7)
5x+7 = 3x+21
2x = 14
X = 7 Yrs. = John's age today.