Question

A math teacher gives her class the following problem.

Barry is selling magazine subscriptions for a school fundraiser. He has already sold 15 subscriptions. He plans to sell 3 subscriptions per week until he reaches a total of 30 subscriptions sold. How many weeks will it take Barry to achieve his goal.

One student in the class solves the problem arithmetically as shown below.




Which algebraic equation could be used to find the same solution?
A.
3 + 15x = 30
B.
3x - 15 = 30
C.
15x - 3 = 30
D.
15 + 3x = 30

Answer 1

D

Explanation:

15 + 3x = 30

If Barry already made 15 subscriptions then we could remove 15 from 30.

30 - 15 = 15

Now, we have 15 subscriptions needed. We can multiply 3 times 5 that would equal 15.

15 + 15 = 30 subscriptions