Question

The water level of a river is 40 feet. The water level is receding at a rate of 0.5 foot per day. In how many days will the water level be 35 feet?

Answer 1

It'll be at 35 feet in 10 days.

Explanation:

since the water level is receding, we change 0.5 to -0.5

we have to add 40 feet, since the water level is 40 feet

w represents 35 since we need to find the number of days the water level will be 35 feet

since w represents total (feet) water and d represents days, we can set up the equation

d = days = -0.5

w = total (feet) water = 35

w = -0.5d + 40

35 = -0.5d + 40

35 - 40 = -0.5d + 40 - 40

-5 = -0.5d

-5/-0.5 = -0.5d/-0.5

10 = d

It'll be at 35 feet in 10 days.

Answer 2

The slope is -.5 which is our rate of change for the water level

The y-intercept is 34 which is our water level after 0 days.

26=-.5d+34

-8=-.5d

16=d

It'll be at 26 in 16 days.

Explanation:

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