Answer:
This means in the first week the number sells of digital copies is 308, paperback sells was 385 copies and hardback sell was 77 copies
Step-by-step explanation:
Let the number of digital copies be x, the number of paperback copies be y and the number of hardback copies be z.
4 digital sales is equal to 5 paperback sales and 1 hardback sale.
5x = 4y, x = 4z, y = 5z
The company sells 308 more paperback copies of the book than hardback copies
y = 308 + z
But y = 5z
5z = 308 + z
4z = 308
z = 77
y = 5z = 5(77) = 385
x = 4z = 4(77) = 308
This means in the first week the number sells of digital copies is 308, paperback sells was 385 copies and hardback sell was 77 copies
