Lourdes,

I'm going to look at the second expression

17 - 2a + 5a - 1.

There are four terms in this expression, 17, -2a, 5a and -1. There is one variable, the letter a.

The constant terms are the terms that don't contain the variable. Thus they are 17 and -1.

The variable terms are the terms that contain the variable. They are -2a and 5a.

The coefficients are the numbers that appear with the variables in the variable terms. In this expression the coefficients are -2 and 5.

Now you try the other three expressions.

Penny