Russel wants to buy 3 identical gift cards. He wants to make sure his total cost is no more than $2 above or below $60. Which of the following inequalities represents this situation?
A|3c − 60| ≤ 2
B|60 + 3c| ≤ 2
C |3c − 2| ≤ 60
D |3c + 2| ≤ 60

Respuesta :

Step-by-step explanation:

very imprecise phrasing.

I assume this means the cost should not be more than $2 above, and not less than $2 below $60.

the bottom line is : the difference between the price of the 3 gift cards and the planned budget of $60 must not be more than $2 (no matter what's the sign of the difference - hence the usage of absolute values).

the only answer calculating that difference and comparing it to the $2 threshold is A.

remember, a difference is always calculated by a "-" operation.

so, B and D disqualify.

C compares the price of the 3 cards with $2 and compares that result with the limit of $60.

yes, that protects against too expensive cards.

but no, it does NOT protect against to cheap cards. e.g. if the cards (3c) cost only $30, that inequality would still be true (but should not).

so, A is the correct answer.