Question 835574: John is 4 times as old as Martha. Five years ago the sum of their ages was 50. how old are they now?
Thanks Michael Answer by hovuquocan1997(83) (Show Source): You can put this solution on YOUR website! Let john's age be "x" and Martha's age be "y"
Based on the question, you have the system of equation
x = 4y
(x-5) + (y-5) = 50 (because it's five years ago)
Then change them to standard form and you have
x-4y = 0
x + y = 60
Now let's solve :)
Solve: We'll use substitution. After moving -4*y to the right, we get: , or . Substitute that
into another equation: and simplify: So, we know that y=12. Since , x=48.
Answer: .
There you go, John is 48 and Martha is 12
TA-DAH
:D