Question

How to do this one..........?????​

Answer 1

Answer:

16 books

Step-by-step explanation:

A shopkeeper buy a books = x books

x books = rs 80

The cost of each books = 80/x      ↔(equation 1)

shopkeeper buy a 4 more books

The total books = x+4

The cost of each books = 80/x+4       ↔ (equation 2)

solving the equations 1 and 2,

        $80​ − x+480​ =1x(x+4)80(x+4)−80x​ =1x 2 +20x−16x−320=0(x−16)(x+20)=0x=16orx=−20$