# Discrete math and proof

1. Sep 3, 2006

Hi,
Please can someone help me with this problem.

show that a,b,c are real numbers and a#0, then there is a unique solution of the equation ax+b=c.

the uniqueness of the solution is my problem.
Thank you
B

2. Sep 3, 2006

### HallsofIvy

Staff Emeritus
If the uniqueness is the problem, then suppose there were two solutions, x1 and x2. Since they are solutions to that equation, you must have, of course, ax1+ b= c and ax2+ b= c. Subtracting one equation from the other, a(x1- x2)= 0. What does that tell you?

3. Sep 3, 2006