Прошу решите уравнение 26 баллов

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$\displaystyle a).. \frac{(a^{5})^{12}*(a^{8})^{7}}{(a^{16})^{8}*(a^{2})^{10}}=256 \\ \\ \frac{a^{60}*a^{56}}{a^{128}:a^{20}}=2^{8} \\ \\a^{116-108}=2^{8} \\ \\ a^{8}=2^{8} \\ \\ a=2 \\ \\ b).. \frac{(x^{17})^{20}:(x^{42})^{5}*x}{(x^{35})^{4}:(x^{2})^{5}}=1968 \\ \\ \frac{x^{340-210+1}}{x^{140-10}}=1968 \\ \\ x^{131-130}=1968 \\ x=1968 \\ \\ c).. \frac{(y^{51})^{3}:(y^{16})^{3}}{(y^{2})^{61}:(y^{4})^{19}*(y^{29})^{2}}=1993 \\ \\ \frac{y^{153-48}}{y^{122-76+58}}=1993\\\\y^{105-104}=1993 \\ y=1993\\$
$\displaystyle d).. \frac{(m^{9})^{22}*(m^{32})^{3}}{(m^{45})^{3}*(m^{3})^{53}:m}=1995 \\ \\ \frac{m^{198+96}}{m^{135+159-1}}= 1995 \\ \\ \frac{1}{m^{-1}}=1995 \\ \\ m=1995$