Question

The water depth in a lake decreases at a rate of 2 inches per day because of evaporation. How much does the water depth change in 8 days? In 15 days? In 8 days, the water depth changes by inches. In 15 days, the water depth changes by inches.

Answer 1

Answer: In 8 days it will decrease by 16 inches and in 15 days the water depth changes by 30 inches.

Explanation:

The water depth decreases at a rate of 2 inches per day so in this case if were to write it as an expression it will be -2x where x is the number of days.

We will have to set it equal the total amount that it has decreased which will be y.

y= -2x If x represent the number of days we will put in the days and solve for y.

y = -2(8)

y = -16 This means that in 8 days it will decrease by 16 inches.

y = -2(15)

y= -30 This also means that in 15 days the water depth changes by 30 inches.