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Решите задачу:

$\frac{ \sqrt{5}* \sqrt{3}-\sqrt{5}- \sqrt{3}+1 }{\sqrt{7}* \sqrt{3}-\sqrt{7}+ \sqrt{3}-1 } = \frac{ (\sqrt{5}* \sqrt{3}-\sqrt{5})- (\sqrt{3}-1) }{(\sqrt{7}* \sqrt{3}-\sqrt{7})+ (\sqrt{3}-1) }= \\ \\ = \frac{ \sqrt{5}*(\sqrt{3}-1)-(\sqrt{3}-1)}{ \sqrt{7}*(\sqrt{3}-1)+(\sqrt{3}-1)} = \frac{(\sqrt{3}-1)*(\sqrt{5}-1)}{(\sqrt{3}-1)*(\sqrt{7}+1)}= \frac{\sqrt{5}-1}{\sqrt{7}+1}$