Math prob...

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Article #373

#373

From: Lloyd Johnston
Date: Wed, 23 Dec 1992 19:47

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EG> Here is a problem I don't really understand how the result is
EG> reached.
EG> Prob.   sqrt(y) + sqrt(y+5) = 5
EG> Ans.  y=4
EG> I see that if you just pop in 4  you get 2+3=5, however I thought
EG> that sqrt(y+5) was the same as sqrt(y) + sqrt(5) giving y=10 which
EG> really baffled me. I could use an explanation of this problem.

Charles:

sqrt(y+5) does not equal sqrt(y) + sqrt (5).  To solve this equation you
need to follow these steps:

Isolate the radicals:

sqrt(y) = 5 - sqrt(y+5)

Square:

y = 25 - 10sqrt(y+5) + y + 5

Simplify:

10sqrt(y+5) = 30

sqrt(y+5) = 3
y + 5 = 9
y = 4

That is how y=4 is obtained.



 # GateOrigin: 89:701/239@imex


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Path: arc1-ca.pugleaf.net!sparky!uunet!psgrain!puddle!p0.f45.n342.z1.fidonet.org!Lloyd.Johnston
From: Lloyd.Johnston@p0.f45.n342.z1.fidonet.org (Lloyd Johnston)
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Subject: Math prob...
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Date: Wed, 23 Dec 92 12:47:01 PDT
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