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:

Step1: Analyze the expression

The expression \(5(15 + (-3))\) represents the net change in the number of residents over 5 years. \(15\) is the number of new residents moving in each year, \(-3\) is the number of residents moving out each year (since \(3\) move away, it's a negative change). So \(15+(-3)\) is the net change per year.

Step2: Analyze the multiplier

The \(5\) in the expression \(5(15 + (-3))\) represents the number of years. When we calculate \(5\times(15 - 3)=5\times12 = 60\), this \(60\) represents the total net change (new residents - residents who moved out) over 5 years.

Answer:

C. After five years, there are 60 new residents in a suburb.