Question

the height of a lake decreases by 20 in over a period of time. the height decreases by 5 in each week. the equation below is written to represent the situation: -20 ÷ (-5) = 4 which description best explains the meaning of 4 in the equation? a the new height of the water in the lake is 4 in. b the change in the height of the lake is 4 in. c the time it takes for the lake to decrease in height by 5 in is 4 weeks. d the time it takes for the lake to decrease in height by 20 in is 4 weeks.

Explanation:

In the equation \(-20\div(-5) = 4\), \(-20\) represents the total decrease in height (\(20\) inches decrease, so negative), \(-5\) represents the rate of decrease per week (\(5\) inches decrease per week, so negative). When we divide the total change in height (\(-20\)) by the rate of change per week (\(-5\)), we get the time. So \(4\) is the number of weeks it takes for the height to decrease by \(20\) inches.

Answer:

D. The time it takes for the lake to decrease in height by \(20\) in is \(4\) weeks.