Part A: variables: these are unknown values usually denoted by letters. (in this case: x,y) Coefficients: the number preceeding a variable that the variable is then multiplied by. (in this problem: 15, 100)
Part B: terms are the combination of a coefficients and a variable. In this instance there are two terms. One term being "15x". The other term being, "100y".
Part C: the term 15x shows her allowence is earned.
