Question

What does the solution 3= -4 imply? This is a question on a test. need help!

Answer 1

The original equation was false; or the method of solution was applied incorrectly.

Example (false equation): 5x+2+3y+1=2x-2+2y-1+3x-1+y is a false equation, no matter what values are given to x and y, because the variables cancel out, leaving the constants:

2+1=-2-1-1, 3=-4 which is false.

Example (method error): 5x+2-3y+1=2x-2+2y-1+3x-1+y, x terms cancel out correctly:

2-3y+1=-2+2y-1-1+y,

3-3y=-4+3y,

INCORRECT: 3=-4 (y's don't cancel out!); CORRECT: 7=6y, y=7/6.