Answer:
and .
Step-by-step explanation:
Let x and y be the numbers of the paperback book and the hardcover book respectively.
as x and y are the counting numbers, so it will be always positive. So,
and
Given that the weight of 1 paperback book=0.8 pounds and
the weight of 1 paperback book=1.3 pounds.
There are at least 20 books in each box, so
As one box cannot weigh more than 30 pounds, so
Now, from the equations (i),(ii),(iii), and (iv), all the sets of constraints as
and .
Moreover, the sets of all the integral values of (x,y) in the shaded region are the feasible numbers of the paperback book and hardcover book.