SOLUTION: Ed bought $2,000 in stock shares one week before the stock price dropped $10.00. If he had waited for the price setback, he could have bought 10 more shares for the same amount. Ho

Question 621264: Ed bought $2,000 in stock shares one week before the stock price dropped $10.00. If he had waited for the price setback, he could have bought 10 more shares for the same amount. How many shares did he buy?
40, 50, or 60?
Found 2 solutions by josmiceli, Emsley:
Answer by josmiceli(19441) (Show Source): You can put this solution on YOUR website!
Let = the price/share before the price dropped
Let = the number of shares he actually bought
given:
(1)
(2)
---------------------------
(1)
Substitute this into (2)
(2)
(2)
(2)
Multiply both sides by
(2)
(2)
(2)
Use quadratic formula

( can't use the negative square root )

He bought 40 shares
check answer:
(1)
(1)
and
(2)
(2)
(2)
(2)
OK
Answer by Emsley(35) (Show Source): You can put this solution on YOUR website!
Let x=original price SO number bought=2000/x
New price=x-10 So number bought= 2000/X-10) This is 10 more than before
So 2000/(x-10)-2000/x =10
Muliply throughout by x(x-10)getting 2000x-2000(x-10)= 10x(x-10)
Divide throughout by and rearrange x^2-10x-2000=0 (x-50)(x+40)=0 So x=50
That is original price was 50 So number bought was 2000/50=40
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