a) \(\frac{9^{10}.27^7}{81^7.3^{15}}\)= \(\frac{\left(3^2\right)^{10}.\left(3^3\right)^7}{\left(3^4\right)^7.3^{15}}\)= \(\frac{3^{2.10}.3^{3.7}}{3^{4.7}.3^{15}}\)=\(\frac{3^{20}.3^{21}}{3^{28}.3^{15}}\)=\(\frac{3^{41}}{3^{43}}\)= \(\frac{3^{41}}{3^{41}.3^2}\)= \(\frac{1}{3^2}=\frac{1}{9}\)

b) \(\frac{8^3.9^5.27^5}{4^5.81^6}\)= \(\frac{\left(2^3\right)^3.\left(3^2\right)^5.\left(3^3\right)^5}{\left(2^2\right)^5.\left(3^4\right)^6}\)= \(\frac{2^{3.3}.3^{2.5}.3^{3.5}}{2^{2.5}.3^{4.6}}\)=\(\frac{2^9.3^{10}.3^{15}}{2^{10}.3^{24}}\)= \(\frac{2^9.3^{25}}{2^{10}.3^{24}}\)=\(\frac{2^9.3^{24}.3}{2^9.2.3^{24}}\)=\(\frac{3}{2}\)

\(A=\frac{7.6^{10}.2^{20}.3^6-2^{18}.6^{15}}{9.6^{19}.2^9-4.3^{17}.2^{26}}=\frac{7.\left(2.3\right)^{10}.2^{20}.3^6-2^{18}.\left(2.3\right)^{15}}{3^2.\left(2.3\right)^{19}.2^9-2^2.3^{17}.2^{26}}\)

                                                        \(=\frac{7.2^{10}.3^{10}.2^{20}.3^6-2^{18}.2^{15}.3^{15}}{3^2.2^{19}.3^{19}.2^9-2^2.3^{17}.2^{26}}\)

                                                         \(=\frac{7.2^{30}.3^{16}-2^{33}.3^{15}}{2^{28}.3^{21}-2^{28}.3^{17}}\)

                                                             \(=\frac{2^{30}.3^{15}.\left(7.3-2^3\right)}{2^{28}.3^{17}.\left(3^4-1\right)}\)

                                                              \(=\frac{2^2.13}{3^2.80}=\frac{4.13}{9.80}=\frac{13}{180}\)

\(A=\frac{7\cdot2^{10}\cdot3^{10}\cdot2^{20}\cdot3^6-2^{18}\cdot2^{15}\cdot3^{15}}{3^2\cdot3^{19}\cdot2^{19}\cdot2^9-2^2\cdot3^{17}\cdot2^{26}}=\frac{7\cdot2^{30}\cdot3^{16}-2^{33}\cdot3^{15}}{3^{21}\cdot2^{28}-2^{28}\cdot3^{17}}\)

\(A=\frac{2^{30}\cdot3^{15}\left(7\cdot3-2^3\right)}{2^{28}\cdot3^{17}\left(3^4-1\right)}=\frac{2^{30}\cdot3^{15}\cdot13}{2^{28}\cdot3^{17}\cdot2^4\cdot5}=\frac{13}{2^2\cdot3^2\cdot5}=\frac{13}{180}\)

Chị ko bt có sai ko nx nếu có sai thông cảm chị nha

^-^

\(B=\frac{7.6^{10}.2^{20}.3^6-2^{19}.6^{15}}{9.6^{19}.2^9-4.3^{17}.2^{26}}\)

\(B=\frac{7.\left(2.3\right)^{10}.2^{20}.3^6-2^{19}.\left(2.3\right)^{15}}{3^2.\left(2.3\right)^{19}.2^9-2^2.3^{17}.2^{26}}\)

\(B=\frac{7.2^{30}.3^{16}-2^{34}.3^{15}}{3^{21}.2^{11}-2^{28}.3^{17}}\)

\(B=\frac{2^{30}.3^{15}.\left(7.3-2^4\right)}{3^{17}.2^{11}.\left(3^4-2^{17}\right)}\)

\(B=\frac{2^{19}.\left(21-2^4\right)}{3^2.\left(3^4-2^{17}\right)}\)

@_@ tự tính!

\(B=\frac{7.\left(2.3\right)^{10}.2^{20}.3^6-2^{19}.\left(2.3\right)^{15}}{3^2.\left(2.3\right)^{19}.2^9-4.3^{17}.2^{26}}\\ B=\frac{7.2^{10}.3^{10}.2^{20}.3^6-2^{19}.2^{15}.3^{15}}{3^2.2^{19}.3^{19}.2^9-2^2.3^{17}.2^{26}}\\ B=\frac{7.2^{30}.3^{16}-2^{34}.3^{15}}{3^{21}.2^{28}-2^{28}.3^{17}}\)   

\(B=\frac{7.2^{30}.3.3^{15}-2^{34}.3^{15}}{3^{15}.3^6.2^{28}-2^{28}.3^{15}.3^2}\\ B=\frac{3^{15}.\left(7.2^{30}.3-3^{34}\right)}{3^{15}.\cdot\left(3^6-3^2\right)}\\ B=\frac{7.2^{30}.3-3^{34}}{3^6-3^2}\)

= 3¹⁴/27³.4²/6⁵

sau đó bạn rút gon đi 

3¹⁴/27³=3¹⁴/3⁹=3⁵         và 4²/6⁵=1/486

 ssau đó: nhân 2 số vs nhau=1/2 hehehehe

mai mik phải nộp rồi ạ   

Bài làm:

Ta có: \(\frac{7.6^{10}.2^{20}.3^6-2^{19}.6^{15}}{9.6^{19}.2^9-4.3^{17}.2^{26}}\)

\(=\frac{7.2^{10}.3^{10}.2^{20}.3^6-2^{19}.2^{15}.3^{15}}{3^2.2^{19}.3^{19}.2^9-2^2.3^{17}.2^{26}}\)

\(=\frac{2^{30}.3^{16}.7-2^{34}.3^{15}}{2^{28}.3^{21}-2^{28}.3^{17}}\)

\(=\frac{2^{30}.3^{15}\left(3.7-2^4\right)}{2^{28}.3^{17}\left(3^4-1\right)}\)

\(=\frac{2^2\left(21-16\right)}{3^2\left(81-1\right)}\)

\(=\frac{2^2.5}{3^2.80}\)

\(=\frac{1}{36}\)

\(B=\dfrac{7.2^{10}.3^{10}2.^{21}.3^6-2^{19}.2^{15}.3^{15}}{3^2.2^{15}.3^{15}.2^{13}-2^2.3^{15}.2^{26}}=\)

\(=\dfrac{2^{31}.3^{15}\left(7.3-2^3\right)}{2^{28}.3^{15}\left(3^2-1\right)}=\dfrac{2^{31}.13}{2^{31}}=13\)

giúp mình với huhu

ai trả lời đúng đầu tiên mình cho 2 tick

\(=4^{15}.5^{15}.5^{15}.3^{19}:3^{12}\)

\(=4^{15}.5^{15}.5^{15}.3^7\)

\(=\left(4.5.5\right)^{15}.3^7\)

\(=100^{15}.3^7\)

có thể mình sai 

\(B=\frac{7.6^{10}.2^{20}.3^6-2^{19}.6^{15}}{9.6^{19}.2^9-4.3^{17}.2^{26}}\)

\(B=\frac{7.3^{16}.2^{30}-2^{34}.3^{15}}{3^{21}.2^{28}-2^{28}.3^{17}}\)

\(=\frac{3^{15}.2^{30}.\left(7.3-2^4\right)}{3^{17}.2^{28}.\left(3^4-1\right)}=\frac{2^2.\left(21-16\right)}{3^2.\left(81-1\right)}=\frac{2^2.5}{3^2.2^4.5}=\frac{1}{3^2.2^2}=\frac{1}{36}\)