Answer:
This is NOT a one solution problem.
Explanation:
Group all terms with a c in it to the left of the equal sign, and group all numbers to the right of the equal sign.
5.7c-1.5+3.2c=7.8c-1.5+1.1c
5.7c + 3.2c - 7.8c - 1.1c = - 1.5 + 1.5
8.9c - 8.9c = 0
0 = 0
No matter which number you substitute for c, it will always be true. Since you can find infinity of solutions, this is NOT a one solution problem.