SAT Question 768b2425: Linear Equations In Two Variables answer and explanation with Desmos solution

Choice A is correct. It's given that $68x+85y=1,258$ represents the situation where an interior designer earned a total of $$1,258$ last week from consulting for $x$ hours and drawing up plans for $y$ hours. Thus, $68x$ represents the amount earned, in dollars, from consulting for $x$ hours, and $85y$ represents the amount earned, in dollars, from drawing up plans for $y$ hours. Since $68x$ represents the amount earned, in dollars, from consulting for $x$ hours, it follows that the interior designer earned $$68$ per hour consulting last week.