Remember that the constant term of an algebraic expression is the term that does not have a variable; the only term that does not have a variable in our algebraic expression is 4, so the constant term of the expression is 4.
The coefficients of an algebraic expression are the terms that accompany the variables (the terms that are next to the variable). For our expression we can infer that the coefficient of

is -1, the coefficient of

is -7, and the coefficient of

is 18.
We can conclude that in the algebraic expression

, the constant term is
4 and the coefficients are
-1,-7,18