Answer:
W ≥ 13 cm represents all the possible width of the book.
Step-by-step explanation:
The width (say W cm) of the rectangular book is 20 cm less than twice its length (say L cm).
So, W = 2L - 20
⇒ 2L = W + 20 .......... (1)
Now, the perimeter of the book is at least 59 cm.
So, 2(L + W) ≥ 59
⇒ 2L + 2W ≥ 59
⇒ W + 20 + 2W ≥ 59 {From equation (1)}
⇒ 3W ≥ 39
⇒ W ≥ 13
Therefore, W ≥ 13 cm represents all the possible width of the book. (Answer)
