Which of the following scenarios could be represented by the expression
12x + 7y?
a. the cost for x adults and y children to go to the movies if adult
tickets are $12 and child tickets are $7.
b. the total weight of a box containing x 7-ounce packages of
almonds and y 12-ounce packages of peanuts.
c. the total number of marbles in a jar if there are 7 green and 12
red.
d. the number of kids in a school class if there are 12 girls and 7
boys.