SAT Question a7e2859a: Linear Functions answer and explanation with Desmos solution

Choice A is correct. It’s given that the cost of renting a large canopy tent is $$430$ for the first day and $$215$ for each additional day for up to $10$ days. For $x$ days of renting the tent, the cost includes $$430$ for the first day and $$215$ for each of the $(x-1)$ additional days. It follows that the cost $y$, in dollars, of renting the tent can be expressed as $y=430+215(x-1)$, which is equivalent to $y=430+215x-215$, or $y=215x+215$. Therefore, the equation $y=215x+215$ gives the cost of renting the tent for $x$ days, where $x$ is a positive integer and $x\le 10$.