PS-2

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PS-2

by sparsh.21 » Wed Jan 14, 2009 9:21 am
If xy ≠ 0 and x2y2 – xy = 6, which of the following could be y in terms of x?

I. 1/(2x)
II. – 2/x
III. 3/x


A. I only
B. II only
C. I and II
D. I and III
E. II and III


OA is E

Please explain the answer
Source: — Problem Solving |

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Re: PS-2

by logitech » Wed Jan 14, 2009 10:16 am
x2y2 – xy - 6 = 0

You can label XY as T

T^2 - T - 6 = 0

(T-3) ( T+2) = 0

XY = 3 ; y=3/x

XY = -2 ; y =-2/x
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