Question 1154580
A bookstore owner bought x pencils for 32 dollars and sold them at a profit of 5 cents per pencil. She ended up with 20 pencils left and received 35 dollars for the sale of the pencils.

How many pencils did he buy.

each pencil costs 32/x dollars

sold at ((32/x) +0.05) $

(x-20)((32/x) +0.05)=35

32-640/x +0.05x -1=35

-640/x +0.05x =4

-640 +0.05x^2 =4x

0.05x^2-4x-640=0

multiply by 100
5x^2-400x-64000=0

x^2-80x -12800=0

(x+80)(x-160)=0

x=-80 or x =160

Number of pencils cannot be negative


pencils bought =160