SOLUTION: 1/x-1/y ________ 1/x+1/y Simplify. When I first attempted this problem, I multiplied the numerators of the fractions that make up the numerator (1-1)of the overall fractions

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: 1/x-1/y ________ 1/x+1/y Simplify. When I first attempted this problem, I multiplied the numerators of the fractions that make up the numerator (1-1)of the overall fractions       Log On


   



Question 629491: 1/x-1/y
________
1/x+1/y Simplify.
When I first attempted this problem, I multiplied the numerators of the fractions that make up the numerator (1-1)of the overall fractions with the denominators of the denominator of the fraction (x + y). I did the same with the numerators of the denominator and the denominator of the numerator, to get x+y/x-y. Seeing that this was one of the answer choices, I assumed it to be correct. I may have been a bit hasty in this, as my answer turned out to be wrong.
Please walk me through this problem so I can solve similar ones on my upcoming math placement exam! Thank you so much.

Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
%281%2Fx-1%2Fy%29%2F%281%2Fx%2B1%2Fy%29 = %28%28y-x%29%2Fxy%29%2F%28%28y%2Bx%29%2Fxy%29
invert the dividing fraction and multiply, the xy cancels:
%28y-x%29%2F%28xy%29 * %28xy%29%2F%28y%2Bx%29 = %28y-x%29%2F%28y%2Bx%29