Conceptual Problem - Manhattan Advanced GMAT Q# 91

[tajamulhussain56]

This question is form Manhattan Advanced GMAT. There seems so be some conceptual problem with the my process of solving.

If |x| != |y|, xy != 0,
x/(x+y) = n, and x/(x-y) = m,
then x/y = ?

i equate the two x and solve

x/(x+y) = n, and x/(x-y) = m, - equation (0)
x=nx+ny ; x=mx-my - equation (1)


on solving above
x/y=(m+n)/(m-n) - equation (2)

i now substitute values for m and n (3,2) and find the value for x/y. The value turns out to be 5.

But when i substitute the same values in the answer choices, none of the them match.

However, if i substitute the values (say 2,3 again) of x and y in equation (0) and find the corresponding values of m and n, and then substitute the values of m and n in the answer choices, the answer matches the value of x/y that i had chosen(2/3).

Im not able to understand why the answers are not matching x/y when i substitute random values of m,n straightaway in equation (2) and why they do so wen i substitute the values of m,n derived from the substituted values of x,y in equation(0)

Can someone please help in trying me understand where i am going wrong .


ANSWER CHOICES
a> 3m/2
b>3m/2n
c>n(m+2)/2
d>2nm/(m-n) This is the right answer
e>n^2-m^2/nm

[StaceyKoprince]

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