Respuesta :

OPKING

Step-by-step explanation:

if 9 boxes is 42.75 then 1 box is 4.75 dollars

so 13 boxes would be 13X3.75 which is 61.75$

if 9b=$42.75

1b=x

9bx=$42.75b

x=$42.75b÷9b

x=$4.75