Answer:
36 pencils
[tex]Cost = 0.2[/tex]
Step-by-step explanation:
Given
Cost Price = 180
Represent the number of items by x
This implies that the cost of each item is [tex]\frac{x}{180}[/tex]
[tex]Selling\ Price = Cost + Profit[/tex]
[tex]Selling\ Price = \frac{x}{180} + 2[/tex]
Since all but 6 items were sold, the total selling price is:
[tex]Total = (x - 6)(\frac{x}{180} + 2)[/tex]
This amount can be used to buy 30 more items.
So, we have:
[tex](x - 6)(\frac{x}{180} + 2) = x + 30[/tex]
Multiply both sides by 180
[tex]180 * (x - 6)(\frac{x}{180} + 2) =180(x + 30)[/tex]
[tex](x - 6)(x + 360) = 180x + 5400[/tex]
Expand brackets
[tex]x\² + 360x - 6x - 2160 = 180x + 5400[/tex]
[tex]x\² + 354x - 2160 = 180x + 5400[/tex]
Equate to 0
[tex]x\² + 354x - 180x - 2160 - 5400 = 0[/tex]
[tex]x\² + 174x - 7560 = 0[/tex]
Expand
[tex]x\² + 210x - 36x - 7560 = 0[/tex]
[tex]x(x + 210) - 36(x + 210) = 0[/tex]
[tex](x - 36)(x + 210) = 0[/tex]
[tex]x - 36 = 0[/tex] or [tex]x + 210 = 0[/tex]
[tex]x = 36[/tex] or [tex]x = -210[/tex]
Since, number of items can't be negative, we have to discard x = -210.
Hence:
[tex]x = 36[/tex]
We can then conclude that, Mr. Javier purchased 36 pencils
Recall that
[tex]Cost = \frac{x}{180}[/tex]
[tex]Cost = \frac{36}{180}[/tex]
[tex]Cost = 0.2[/tex]
