Respuesta :
24 - ( 1+3 ) = 20.
20 + b(book weight; unknown) = answer
Since 4 x 5 is 20, the answer is that Toni can carry 5 books.
20 + b(book weight; unknown) = answer
Since 4 x 5 is 20, the answer is that Toni can carry 5 books.