I don’t know how to do that

16

Step-by-step explanation:

Divide 64 by 8 to get 8. this is 1/8 of the books.

3/8 were non fiction, or 24

1/4 (2/8) were picture books, or 16

5/8 were non fiction or picture books, so ’the rest‘ of the chapter books is 3/8.

3/8 were chapter books, or 24.

add the amount of picture books and chapter books since they are the fictional texts.

16+24=40

subtract the amount of non fictional books from the amount of fictional books to get the sum.

40-24=16

  2087568668/1  

step-by-step explanation:

he used the algebra tiles correctly.

step-by-step explanation:

given : 3x(2x-1)

solution :

since he used algebra tiles .

armando's solution is the same in the solution shown in figure

as he distributed 2x into x and x and wrote them vertically

and also write   -1 vertically

and 3x into x and x and x and wrote it horizontally

performing the multiplication in the algebra tiles we get

and solving the given expression :

3x(2x-1)

since solving the expression using tiles   and solving the expression algebraically we get the same answer

thus   we can choose the first statement as the answer to this problem which is "he used the algebra tiles correctly".