Question

I know this is simple, that probably why I am unsure of the answer.
d/r+d-d/r-d=

Answer 1

\[\frac{d}{r+d}-\frac{d}{r-d}????\]

Answer 2

\[\frac{d}{r+d}-\frac{d}{r-d}= d(\frac{1}{r+d}-\frac{1}{r-d})\]
: P

Answer 3

subtract and simplify

Answer 4

\[\frac{d(r-d)-d(r+d)}{(r-d)(r+d)}\]

Answer 5

\[\frac{-2d^2}{(r-d)(r+d)}\]

Answer 6

\[\frac{d(r-d)-d(r+d)}{(r+d)(r-d)}\]
\[\frac{dr-d^2-dr-d^2}{r^2-d^2}=\frac{-2d^2}{r^2-d^2}\]