Hi:

I am looking for confirmation that I have done this problem correctly:

6-(-5r)=5r-3
6+5r=5r-3
6+3+5r=5r-3+3
9+5r=5r
9+5r-5r=5r-5r
9=0

6-(-5r)=5r-3

6+5r=5r-3 OK TO HERE.
6+3+5r=5r-3+3
9+5r=5r
9+5r-5r=5r-5r
9=0
The equation is faulty because 5r on one side cancels with 5r on the other and division by zero is not allowed.