a: \(A=\dfrac{2^{10}\cdot3^8-2^2\cdot2^{27}\cdot3^{20}}{5\cdot2^{10}\cdot2^{12}\cdot3^{12}-7\cdot2^{29}\cdot3^{18}}\)
\(=\dfrac{2^{10}\cdot3^8-2^{29}\cdot3^{20}}{5\cdot2^{22}\cdot3^{12}-7\cdot2^{29}\cdot3^{18}}\)
\(=\dfrac{2^{10}\cdot3^8\left(1-2^{19}\cdot3^{12}\right)}{2^{22}\cdot3^{12}\left(5-7\cdot2^7\cdot3^6\right)}=\dfrac{1}{2^{12}}\cdot\dfrac{1}{3^4}\cdot\dfrac{1-2^{19}\cdot3^{12}}{5-7\cdot2^7\cdot3^6}\)
a: A=210⋅38−22⋅227⋅3205⋅210⋅212⋅312−7⋅229⋅318A=210⋅38−22⋅227⋅3205⋅210⋅212⋅312−7⋅229⋅318
=210⋅38−229⋅3205⋅222⋅312−7⋅229⋅318=210⋅38−229⋅3205⋅222⋅312−7⋅229⋅318
=210⋅38(1−219⋅312)222⋅312(5−7⋅27⋅36)=1212⋅134⋅1−219⋅3125−7⋅27⋅36
