OG详解-OG7 数学1 Q28

Choice A is correct. It’s given that the graph shown gives the estimated value y, in dollars, of a tablet as a function of the number of months since it was purchased, x. The y-intercept of a graph is the point at which the graph intersects the y-axis, or when x is 0. The graph shown intersects the y-axis at the point  (0, 225). It follows that 0 months after the tablet was purchased, or when the tablet was purchased, the estimated value of the tablet was 225 dollars. Therefore, the best interpretation of the y-intercept is that the estimated value of the tablet was $225 when it was purchased.
Choice B is incorrect. The estimated value of the tablet 24 months after it was purchased was $50, not $225. Choice C is incorrect. The estimated value of the tablet had decreased by $225-$50, or $175, not $225, in the 24 months after it was purchased. Choice D is incorrect and may result from conceptual errors.