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:
$(-10)\cdot3=-30$
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: Residents leaving is represented by -10 per year, not -30 directly as a count of leaving.
• Option B: Number of residents can't be negative in a real - world context.
• Option C: Change per year is -10, not -30.
• Option D: Since 10 residents leave each year for 3 years, total change is (-10)×3 = -30.

Answer:

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