SOLUTION: (1) ax + by = c (2) dx + ey = f Ralph is trying to solve the system of equations. He begins by subtracting Ax from both sides of equation (1), and then he divides the eq

Ralph does this:

(1)   ax + by = c
     -ax         -ax
     ---------------
           by = c-ax

So he does this:

         
           

She is wrong to tell him that he will get the wrong answer, 
because he will get the right answer if he substitutes 
 for y in equation (2) like this:




Then multiply by LCD of b


Get terms in x on the left:

Factor out x on the left:

Divide both sides by (bd-ea)



Now although Alice was wrong to tell Ralph that
he would get the the wrong answer, the way she
said to do it would have been just as good. She 
would have gotten the same answer as Ralph. She 
would have found x first and y second, whereas
Ralph found y first and x second.

Edwin