SAT Question 6e50ce28: Systems of Linear Equations answer and explanation with Desmos solution

Choice B is incorrect. The equation $y=3-x$ describes a situation where the number $y$ is $x$ less than $3$.

Choice C is incorrect. The equation $2\left(x+7\right)=y$ describes a situation where the number $y$ is twice the sum of a number $x$ and $7$.

Choice D is incorrect. The equation $2\left(x+7\right)=y$ describes a situation where the number $y$ is twice the sum of a number $x$ and $7$, and the equation $y=3-x$ describes a situation where a number $y$ is $x$ less than $3$.