The variable is the letter like x or y. The coefficient is the number next to the variable like the 2 in 2x or if its just x it would be 1. The constant is the number by itself usually at the end.
Example 2x+5
Variable is x constant is 5 and coefficient is 2. Sorry i didn't answer the actual question and just told you how to find it but those expressions don't have any of these things.