SOLUTION: 39. A professor is three times as old as one of his pupil, Louis. Four years ago he was four times as old as Louis was at that time. How old is Louis?
Algebra ->
Customizable Word Problem Solvers
-> Age
-> SOLUTION: 39. A professor is three times as old as one of his pupil, Louis. Four years ago he was four times as old as Louis was at that time. How old is Louis?
Log On
Question 926443: 39. A professor is three times as old as one of his pupil, Louis. Four years ago he was four times as old as Louis was at that time. How old is Louis?
You can put this solution on YOUR website! x = professor age now
y = pupil age now
---
x = 3y
x - 4 = 4(y - 4)
---
put the system of linear equations into standard form
---
x = 3y
x - 4 = 4y - 16
---
x - 3y = 0
x - 4y = -12
---
copy and paste the above standard form linear equations in to this solver:
https://sooeet.com/math/system-of-linear-equations-solver.php
---
solution:
x = professor age now = 36
y = pupil age now = 12
---
Solve and graph linear equations:
https://sooeet.com/math/linear-equation-solver.php
---
Solve quadratic equations, quadratic formula:
https://sooeet.com/math/quadratic-formula-solver.php
---
Solve systems of linear equations up to 6-equations 6-variables:
https://sooeet.com/math/system-of-linear-equations-solver.php
