value of x

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value of x

by maihuna » Sun Sep 13, 2009 6:13 am
If x^2-y = w, what is the value of x?
(1) w + y = 4
(2) y = 1
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by DanaJ » Sun Sep 13, 2009 7:26 am
x^2 - y = w means that x^2 = w + y.

1. tells us that w + y = x^2 = 4, which means that x can be either 2 or -2. Not sufficient.

2. the value of y alone is not enough to determine x^2, let alone x.

Together they're of not much use either. Answer E.