SAT Question cea27ab2: Linear Equations In Two Variables answer and explanation with Desmos solution

Choice A is correct. To verify which table represents this linear relationship, the values in each table can be checked by substituting them into the given equation. The table in choice A shows that when $x=0$, $y=21$. Substituting these values into the given equation yields $7(0)-4(21)=-84$, or $-84=-84$, which is true. Additionally, the table in choice A shows that when $x=4$, $y=28$. Substituting these values into the given equation yields $7(4)-4(28)=-84$, or $-84=-84$, which is true. Finally, the table in choice A shows that when $x=8$, $y=35$. Substituting these values into the given equation yields $7(8)-4(35)=-84$, or $-84=-84$, which is true. Therefore, the table in choice A gives three values of $x$ and their corresponding values of $y$.