Алгебраические дроби (40 баллов!)

$\displaystyle A6)..\frac{m^{2}n}{15p}*\frac{5p}{mn^{2}}=\frac{m}{3n};\\\\A7)..\frac{5m-25}{3p+5}:\frac{m^{2}-25}{6p+10}=\frac{5(m-5)}{3p+5}*\frac{2(3p+5)}{(m-5)(m+5)}=\frac{10}{m+5};\\\\A8)..(-\frac{3b^{2}}{n^{2}})^{3}=-\frac{27b^{6}}{n^{6}};\\\\A9)..(2+\frac{m}{m+1})*\frac{3m^{2}+3m}{12m+8}=\frac{3m+2}{m+1}*\frac{3m(m+1)}{4(3m+2)}=\frac{3m}{4};\\\\A10)..\frac{y+1}{y-3}-1=\frac{7}{y}\\\\\frac{y+1-y+3}{y-3}-\frac{7}{y}=0$

$\displaystyle \frac{4y-7(y-3)}{y(y-3)}=0 \\ \\ \frac{-3y+21}{y(y-3)}=0 \\ \\ odz:y \neq 0;y \neq 3 \\ \\ 21-3y=0 \\y=7$

Ответ:{7}

$\displaystyle A11)..8x^{-3}y^{8}z^{-2}= \frac{8y^{8}}{x^{3}z^{2}}; \\ \\ A12).. \frac{19a^{-15}}{33b^{-14}}* \frac{11b^{-11}}{76a^{-17}}= \frac{19b^{14}*11a^{17}}{33a^{15}*76b^{11}} =\frac{b^{3}a^{2}}{12};$