SAT Question dfa45424: Linear Equations In Two Variables answer and explanation with Desmos solution

Choice D is correct. Since a $10$-ride pass costs $$12.50$ and $g$ is the number of $10$-ride passes Tony buys in a month, the expression $12.50g$ represents the amount Tony spends on $10$-ride passes in a month. Since a single-ride pass costs $$1.50$ and $t$ is the number of single-ride passes Tony buys in a month, the expression $1.50t$ represents the amount Tony spends on single-ride passes in a month. Therefore, the sum $12.50g+1.50t$ represents the amount he spends on the two types of passes in a month. Since Tony spends a total of $$80$ on passes in a month, this expression can be set equal to $80$, producing $12.50g+1.50t=80$.