Х2-2х+1/х2-1=(х-1)2/(х-1)(х+1)=х-1/х+1
5m2+10mn+5n2/15m2-15n2=5(m2+2mn+n2)/15(m-n)(m+n)=(m+n)2/3(m-n)(m+n)=m+n/39m-n)
<h3><em>Решение приложено</em></h3>
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Ответ
&/$##@#$///$#@$//$#@$//#@
7a/6c -(49a²+36c²)/42ac+(6c-49a)/7a=
=(49a²-49a²-36c²+36c²-6c*49a)/42ac=-6c*49a/42ac=-7