Answer: See Explanation below
Step-by-step explanation: 5c² + 7d
Considering the expression above, the coefficients are numbers that multiply the variables (letters). Thus, 5 is a coefficient (it is the coefficient in the term 5x²) and 7 is also a coefficient (it is the coefficient in the term 7d).
Now like terms contain the same variable (letter) raised to the same power. In 5c² + 7d, the terms are 5c² and 7d have different variables (no letter in common) so there are no like terms.
Constants are terms without variables e.g. 1, 2, -5,...etc. So in the expression there's none whatsoever.
For exponents, the number by which a value (called the base) is said to be raised to a power in exponentiation: for example, the 2 in 5c².