Respuesta :

Answer:

B. 24x + 38

Step-by-step explanation:

Since this is a rectangle, there will be a pair of sides that are the same. With perimeter, add up the side lengths.

[tex]2(9x+12)+2(3x+7)\\\\18x+24+6x+14\\\\24x+38[/tex]

24x+38

I just doubled each side and got this