Answer:
The teacher gained 2 pounds per year (Option A)
Step-by-step explanation:
Teacher's weight in 1999 = 148 lbs
Teacher's weight in 2020 = 190 lbs
Let the year be represented by x
Let the weight be represented by y
x₁ = 1999, y₁ = 148, x₂ = 2020, y₂ = 190
The rate of change in weight is given by the formula below
![\begin{gathered} \text{Rate = }(y_2-y_1)/(x_2-x_1) \\ \text{Rate = }(190-148)/(2020-1999) \\ \text{Rate = }(42)/(21) \\ \text{Rate = 2} \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/2knc2lnr379uemmtfje04ewipthcafaa9v.png)
Since the rate of change in weight = 2 lbs/yr, this means that the teacher gained 2 pounds per year