Answer:
y = -2x + 22
Explanation:
You fill an aquarium with water, the water is 22 inches deep. The water evaporates at 2 inches per week. Write an equation that approximates the depth y of water in the aquarium x weeks after you fill it.
Answer: The problem above represents that of a linear function. The equation of a linear function is given by:
y = mx + b, where y is the dependent variable, x is the independent variable, m is the rate of change and b is the initial value of y when x = 0.
From the problem, the independent variable is the number of weeks and the dependent variable is the depth of water, hence y = depth of water and x = weeks after you fill it.
The rate = 2 inches per week, since it evaporates (decreases), hence m = rate of change = -2. Also, at 0 weeks (x = 0), the depth (y) = 22 inches, therefore b = 22. Using the equation for linear function, we get:
y = -2x + 22