The graph shows the number of gallons in a wading pool that is being drained. Using the points (1,160) and (3,80) as (x1,y1) and (x2,y2) , what is the rate of change in the number of gallons in the pool after each hour has passed? (1 point) Responses 40 gal./hr. 40 gal./hr. 140 gal./hr. Start Fraction 1 over 40 End Fraction gal./hr. −40 gal./hr. negative 40 gal./hr. −140 gal./hr.

1 answer

To find the rate of change, we need to find the slope of the line passing through the points (1,160) and (3,80). The slope is defined as the change in y divided by the change in x.

Change in y = 80 - 160 = -80
Change in x = 3 - 1 = 2

Slope = change in y / change in x
Slope = -80 / 2 = -40

Therefore, the rate of change in the number of gallons in the pool after each hour has passed is -40 gallons per hour.