SOLUTION: Please help me with this application problem: Mary is three times as old as her son. in 12 years, Mary's age will be one year less than twice her sons age. How old is each now?

Algebra ->  Customizable Word Problem Solvers  -> Age -> SOLUTION: Please help me with this application problem: Mary is three times as old as her son. in 12 years, Mary's age will be one year less than twice her sons age. How old is each now?      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


    

Question 703058: Please help me with this application problem:
Mary is three times as old as her son. in 12 years, Mary's age will be one year less than twice her sons age. How old is each now?
Answer by MathLover1(20849) About Me  (Show Source):
You can put this solution on YOUR website!

let Mary's age be x and her son's age y
given:

Mary is three times as old as her son: x=3y.......eq.1

in 12 years, Mary's age will be one year less than twice her sons age:
x%2B12=2%28y%2B12%29-1.......eq. 2
solve this system:
x=3y.......eq.1
x%2B12=2%28y%2B12%29-1.......eq. 2
_____________________________
x%2B12=2%28y%2B12%29-1.......eq. 2...substitute x from eq. 1
3y%2B12=2%28y%2B12%29-1
3y%2B12=2y%2B24-1
3y-2y=24-12-1
y=11.......son's age
and
x=3y
x=3%2A11
x=33.......Mary's age