SOLUTION: Five years from now, a father's age will be three times his son's age, and five years ago, he was seven times as old as his son was. How do I set up this problem to solve as a sys

Question 846191: Five years from now, a father's age will be three times his son's age, and five years ago, he was seven times as old as his son was. How do I set up this problem to solve as a system?
Answer by ankor@dixie-net.com(22740) (Show Source): You can put this solution on YOUR website!
Let f = father's age
let s = son's age
:
Write an equation for each statement, smplify.
:
"Five years from now, a father's age will be three times his son's age,"
f + 5 = 3(s+5)
f + 5 = 3s + 15
f = 3s + 15 - 5
f = 3s + 10
"and five years ago, he was seven times as old as his son was."
f - 5 = 7(s-5)
f - 5 = 7s - 35
f = 7s - 35 + 5
f = 7s - 30
Use this to replace f in the 1st equation
7s - 30 = 3s + 10
You should be able to solve this now. Check your solutions in both statements

How do I set up this problem to solve as a system?
RELATED QUESTIONS
Five years from now, a father's age will be three times his son's age, and five years... (answered by stanbon,pedjajov)

Five years from now, a father's age will be three times his son's age, and 5 years ago,... (answered by fractalier)

five years from now a father's age will be three times his son's age, and 5 years ago, he (answered by Alan3354)

five years ago a man was seven times as old as his son. five years hence, the father will (answered by ankor@dixie-net.com)

after five year, the age of a father will be thrice the age of his son, whereas five... (answered by JulietG)

Q:A father is now four times as old as his son. Five years ago, he was seven times as old (answered by josgarithmetic)

five years ago a man was seven times as as old as his son.five years hence, the father... (answered by jorel555)

two years ago , a father was five times old as his son . two years later from today his... (answered by ankor@dixie-net.com)

a father is now four times as old as his son. five years ago he was seven times as old as (answered by stanbon)