March 15, 1999
Problem of the Week

The Simultaneous Equations Problem

Solve the following simultaneous equations for x and y:

  7a      5a      11  
  ---  +  ---  =  ---
   x       y       4

          and

  5a      2a      17  
  ---  -  ---  =  ---
   x       y      20
     
             

Solution to the Problem:

x = 4a

y = 5a       x, y, a can not = 0

To solve: Multiply the top equation by 2 and the bottom equation by 5.   Adding will eliminate the term with 10a/y in it.
Then solve for x in terms of a.

Correctly solved by:

1. Dave Manning

Coopersburg, PA (Lehigh University)

Send any comments or questions to: David Pleacher