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信息发布者:
解:​$(1)$​第​$n$​式为​$\frac {1}{\sqrt {n+1}+\sqrt {n}}=\sqrt {n+1}-\sqrt {n}$​
​$ (2)$​原式​$=(\sqrt {2}-1)+(\sqrt {3}-\sqrt {2})+(\sqrt {4}-\sqrt {3})+·s+(\sqrt {10}-\sqrt {9})=\sqrt {10}-1$​