Question

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Answer 1

$\frac{u^{2}-100}{6u^{2}+1} *(\frac{60u+1}{u-10} +\frac{60u-1}{u+10} )=\frac{(u-10)(u+10)}{6u^{2}+1} *(\frac{(60u+1)(u+10)}{(u-10)(u+10)} +\frac{(60u-1)(u-10)}{(u-10)(u+10)} )=\\\\=\frac{(u-10)(u+10)}{6u^{2}+1} *(\frac{60u^{2}+601u+10+60u^{2}-601u+10}{(u-10)(u+10)} )=\frac{(u-10)(u+10)}{6u^{2}+1} *\frac{120u^{2}+20}{(u-10)(u+10)} =\\\\=\frac{20(6u^{2}+1)}{6u^{2}+1} =20$