DS problem in stat2

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DS problem in stat2

by vishalwin » Sat Oct 03, 2015 8:32 am
Is (x^3)/y = x + x/y?

a) y=8
b) y = (x^2) - 1

Can anyone explain this DS problem?

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by theCEO » Sat Oct 03, 2015 8:55 am
vishalwin wrote:Is (x^3)/y = x + x/y?

a) y=8
b) y = (x^2) - 1

Can anyone explain this DS problem?
Let simplify (x^3)/y = x + x/y

(x^3)/y = x + x/y
(x^3)/y - (x/y) = x
x/y * (x^2 - 1) = x
1/y * (x^2 - 1) = 1
(x^2 - 1) = y

Rephrased question: is (x^2 - 1) = y

a)y = 8
(x^2 - 1) = 8
We don't know what x is, so we cant answer this part
not sufficient

b)y = (x^2) - 1
this is equal to the rephrased question
sufficent

ans = b