We can represent the length in Zach's car model by x
Since we have been given that Ginny's car is 2 more than 3 times the length of Zach's car, then we can get the expression as follow
[tex]\begin{gathered} 3\text{ times the length of Zach's car is} \\ 3\times x=3x \\ \end{gathered}[/tex][tex]\begin{gathered} 2\text{ more than 3 times the length of Zach's car will be} \\ 2+3x \end{gathered}[/tex]Therefore,
Ginny's model will be 2 + 3x
Next, we are told that the sum of the lengths of both cars is 30 inches
Then
[tex]\begin{gathered} Zach\text{+}Ginny=30 \\ x+2+3x=30 \end{gathered}[/tex]Therefore,
The answer is
[tex]x+2+3x=30[/tex]Thus, the answer is Option B