Question 1023723: You drive at an average speed of 50mph to a discount shopping mall, spend two hours shopping, and then return at an average speed of 25mph. The entire trip take 8 hours. How far away is the shopping mall?
Found 2 solutions by ikleyn, josmiceli:
Answer by ikleyn(52771)   (Show Source):
You can put this solution on YOUR website! .
The sum of two numbers is 9 and the difference of their squares is 9. Find the numbers.?
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x + y = 9, (1)
 = 9. (2)
Rewrite (2) in the form
(x+y)*(x-y) = 9,
then replace (x+y) by 9, due to (1). You will get
9*(x-y) = 9.
Next, reduce both sides by the factor 9. You will get
x - y = 1. (3)
Now, you have thwo equations to solve,
x + y = 9, (1')
x - y = 1. (3')
Add them. You will get 2x = 9 + 10 ---> 2x = 10 ---> x =  = 5.
Then from (1') y = 9 - x = 9 - 5 = 4.
Answer. x = 5, y = 4.
Answer by josmiceli(19441)  (Show Source):
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