Answer:
A.
x + y = 28
1.68x + 2.44y = 54.64
Explanation:
Let x = paperback books and y = hardback books
x+y =28
We know that paperbacks cost 1.68 and hardback cost 2.44
1.68x + 2.44y = 54.64
We have 2 equations and 2 unknowns
x+y =28
1.68x + 2.44y = 54.64