Question

10. Which expression represents the cost of x pencils at $0.08 each and y notebooks at $1.70

each?
a. $1.78xy
b. $1.78(x + y)
c. $0.08x + $1.70 y
d. x + y +$1.78
e. $0.08 y + $1.70x

Answer 1

C

Explanation:

A, B, and D are all incorrect. The thing is you have to keep the pencils and notebooks separate. Then you add the totals of each. Anything that combines either the cost of one pencil and 1 notebook (such as B 1.78 (x + y) is incorrect.

D is kind of a special case, but it is not correct. The price of one notebook and 1 pencil is $1.78. But then you add 1 pencil and 1 notebook and you get some sort of odd term.

E is wrong. It would be right is y and x were interchanged so the x would go with 0.08

That leaves C which is the correct way to write it.