Question

in suburbs of large cities,15 new residents move in each year. of those 15, three will move away each year. which of the of the following best describes the meaning of 60, from the expression: 5(15 + (-3)) = 60? a each year 60 new residents move into the suburb. b after five years, 60 new residents have already moved out of a certain suburb. c after five years, there are 60 new residents in a suburb. d over five years, 60 residents first move in, then move out of the suburb.

Explanation:

Step2: Consider the multiplier
The number \(5\) represents the number of years. When we calculate \(5\times12 = 60\), it means that over \(5\) years, with a net increase of \(12\) residents per year, the total number of new residents in the suburb is \(60\).

• Option A: Incorrect because \(60\) is not the annual number (annual net is \(12\)).
• Option B: Incorrect because it's a net increase, not the number moving out.
• Option D: Incorrect because it's a net result, not a first - in - then - out count.

Answer:

Step2: Consider the multiplier
The number \(5\) represents the number of years. When we calculate \(5\times12 = 60\), it means that over \(5\) years, with a net increase of \(12\) residents per year, the total number of new residents in the suburb is \(60\).

• Option A: Incorrect because \(60\) is not the annual number (annual net is \(12\)).
• Option B: Incorrect because it's a net increase, not the number moving out.
• Option D: Incorrect because it's a net result, not a first - in - then - out count.