SOLUTION: if x+y = 3 and x^2-y^2 = 6 what is the value of the reciprocal of 1/(x-y) a 1/6 b 1/3 c 1/2 d 2 e 3

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: if x+y = 3 and x^2-y^2 = 6 what is the value of the reciprocal of 1/(x-y) a 1/6 b 1/3 c 1/2 d 2 e 3      Log On


   

Question 310274: if x+y = 3 and x^2-y^2 = 6 what is the value of the reciprocal of 1/(x-y)
a 1/6 b 1/3 c 1/2 d 2 e 3
Answer by Edwin McCravy(20062) About Me  (Show Source):
You can put this solution on YOUR website!
if x+y = 3 and x^2-y^2 = 6 what is the value of the reciprocal of 1/(x-y)
a 1/6 b 1/3 c 1/2 d 2 e 3 

x%5E2-y%5E2=6
%28x%2By%29%28x-y%29=6
3%28x-y%29=6
x-y=2

This is a trick question, because you ordinarily think of 1%2F%28x-y%29
as already being a reciprocal and you might be tricked into thinking
that the answer is the reciprocal of 2, and answer c.  However,
the reciprocal of 1%2F%28x-y%29 is %28x-y%29%2F1 and that is the same as
x-y and the correct choice is answer d 2.

Edwin