SAT Question c8fb6bcb: Linear Functions answer and explanation with Desmos solution

Choice B is correct. It's given that $f\left(x\right)=2x+244$ represents the perimeter, in $\text{centimeters}(\text{cm})$, of a rectangle with a length of $x$ cm and a fixed width. If $w$ represents a fixed width, in $\text{cm}$, then the perimeter, in $\text{cm}$, of a rectangle with a length of $x$ cm and a fixed width of $w$ cm can be given by the function $f\left(x\right)=2x+2w$. Therefore, $2x+2w=2x+244$. Subtracting $2x$ from both sides of this equation yields $2w=244$. Dividing both sides of this equation by $2$ yields $w=122$. Therefore, the width, in $\text{cm}$, of the rectangle is $122$.