Welcome 2016! Part 21

Algebra Level 3

$\large \dfrac{5}{1 \times 3}+\dfrac{5}{2\times 4}+\dfrac{5}{3 \times 5}+\dfrac{5}{4\times 6}+\cdots = \dfrac{A}{B}$

Given that $$A$$ and $$B$$ are coprime positive integers, find $$A-B$$.

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