Devon has 80 books to pack in boxes she packs 20 books in each box hiw many boxes does she need . write an equation using the letter n to stand for the unknown factor. explain how to find the unknown factor

see the explanation

Step-by-step explanation:

Let

n ----> the number of boxes needed

we know that

The number of boxes needed  (n) multiplied by the number of books in each box (20 books) must be equal to the total books Devon has (80 books)

so

The linear equation that represent this situation is

Solve for n

Divide by 20 both sides

therefore

The number of boxes needed are 4

walter needs to make at least 5 more cookies but no more than 40. 5 ≤ x ≤ 40

step-by-step explanation:

20 ≤ x + 15 ≤ 55

subtract 15 from all parts

20-15 ≤ x + 15-15 ≤ 55-15

5 ≤ x ≤ 40

this means how many more cookies he has to make

walter needs to make at least 5 more cookies, but no more than 40 cookies; 5 ≤ x ≤ 40

a=24; b=12

step-by-step explanation:

a/b=2: 1

a=2b

36/(1+2)=12

b=12

a=24