Answer:
-3c^2 +6
Explanation:
The equation will be an identity (0=0) when M is equal to the contents of the parentheses. That polynomial can be used directly, or it can be simplified by combining the c^2 terms.
The contents of parentheses simplify as follows:
... (4c^2 -7c^2 +6) = (c^2(4 -7) +6) = (-3c^2 +6)