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:

• Option A: Saying “-30 residents leave” is an incorrect way of phrasing. We don't say a negative number of residents leave in this context.
• Option B: Having -30 residents in a town is not a meaningful real - world description as the number of residents can't be negative in this sense.
• Option C: The change per year is -10 (since 10 leave each year), not -30.
• Option D: Since 10 residents leave each year for 3 years, the total change (which is a decrease) is calculated as \((- 10)\times3=-30\). This means the total change in the number of residents due to people moving away is -30.

Answer:

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