Question

in a small town, 10 residents move to new cities each year for 3 years. the equation below is written to represent the situation: (-10)·3 = -30 which description best explains the meaning of -30 in the equation? a -30 residents leave the town. b there are -30 residents in the town. c the change in the number of residents per year is -30. d the total change in the number of residents in the town due to people moving away is -30.

Explanation:

Step1: Analyze the meaning of each part of the equation

The $-10$ represents the number of residents leaving per year (negative because it's a decrease). The $3$ represents the number of years.

Step2: Analyze the product

When we multiply $(-10)\times3=-30$, the result represents the total change over the 3 - year period. It's not the number of residents per year (so C is wrong), a town can't have a negative number of residents (so B is wrong), and it's not just the number leaving (A is too simplistic). The $-30$ is the total change in the number of residents in the town over 3 years due to people moving away.

Answer:

D. The total change in the number of residents in the town due to people moving away is $- 30$.