SOLUTION: HELP. I don't get real number stuff or how to do this problem. Cab you help me? Prove: For all real numbers a,b, and c, if a+c = b+c, then a = b

Algebra ->  Real-numbers -> SOLUTION: HELP. I don't get real number stuff or how to do this problem. Cab you help me? Prove: For all real numbers a,b, and c, if a+c = b+c, then a = b      Log On


   

Question 87235: HELP. I don't get real number stuff or how to do this problem. Cab you help me?
Prove: For all real numbers a,b, and c, if a+c = b+c, then a = b
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
Just treat each letter as a variable. So if we have:

a%2Bc=b%2Bc

then lets try to get

a=b

by algebraically manipulating the given equation


a%2Bc=b%2Bc Start with the given equation

a%2Bc-c=b%2Bc-c Subtract c from both sides

a%2Bcross%28c-c%29=b%2Bcross%28c-c%29 Notice the c terms cancel out

a%2B0=b%2B0 The c terms add and cancel out to zero

a=b Remove the zeros

So this proves that if a%2Bc=b%2Bc, then a=b