Bạn cho mình hỏi là 5.4 vs mấy cái tương tự là 5 nhân 4 hay 5,4 vậy?

5 nhân 4 

Lớp sáu như thế mà

\(\dfrac{5.4^{15}.9^9-4.3^{20}.8^9}{5.2^9.6^{19}-7.2^{29}.27^6}=\dfrac{5.2^{30}.3^{18}-2^2.3^{20}.2^{27}}{5.2^9.2^{19}.3^{19}-7.2^{29}.3^{18}}=\dfrac{2^{29}.3^{18}\left(5.2-3^2\right)}{2^{28}.3^{18}\left(5.3-7.2\right)}=\dfrac{2^{29}.3^{18}}{2^{28}.3^{18}}=\dfrac{2^{29}}{2^{28}}=2^1=2\)

có câu hỏi đâu bạn!

Sửa đề:\(\dfrac{5\cdot4^{15}\cdot9^9-4\cdot3^{20}\cdot8^9}{5\cdot2^9\cdot6^{19}-7\cdot2^{29}\cdot27^6}\)

\(=\dfrac{5\cdot2^{30}\cdot3^{18}-3^{20}\cdot2^{29}}{5\cdot2^9\cdot3^{19}\cdot2^{19}-7\cdot2^{29}\cdot3^{18}}\)

\(=\dfrac{3^{18}\cdot2^{29}\cdot\left(5\cdot2-9\right)}{2^{28}\cdot3^{18}\cdot\left(5\cdot3-7\cdot2\right)}=2\)

\(A=\dfrac{5.4^{15}.9^9-4.3^{20}.8^9}{7.2^{29}.27^6-5.2^9.6^{19}}\)

\(A=\dfrac{5.2^{30}.3^{18}-2^2.3^{20}.2^{27}}{7.2^{29}.3^{18}-5.2^9.2^{19}.3^{19}}\)

\(A=\dfrac{2^{29}.3^{18}.\left(5.2-3^2\right)}{2^{28}.3^{18}.\left(7.2-5.3\right)}\)

\(A=\dfrac{2.\left(10-9\right)}{14-15}=\dfrac{2}{-1}=-2\)

Chúc bạn học tốt!!!

\(A=\dfrac{5.4^{15}.9^9-4.3^{20}.8^9}{7.2^{29}.27^6-5.2^9.6^{19}}=\dfrac{5.\left(2^2\right)^{15}.\left(3^2\right)^9-2^2.3^{20}.\left(2^2\right)^9}{7.2^{29}.27^6-5.2^9.\left(2.3\right)^{19}}\)

\(=\dfrac{5.2^{30}.3^{18}-2^2.3^{20}.2^{27}}{7.2^{29}.3^{18}-5.2^9.2^{19}.3^{19}}\)

\(=\dfrac{2^{29}.3^{18}\left(5.2-3^2\right)}{2^{28}.3^{18}\left(7.2-5.3\right)}\)

\(=\dfrac{2\left(10-9\right)}{14-15}=\dfrac{2}{-1}=-2\)

\(\dfrac{5.4^{15}.9^9-4.3^{20}.8^9}{5.2^9.6^{19}-7.2^{29}.27^6}\)

\(=\dfrac{5.\left(2^2\right)^{15}.\left(3^2\right)^9-2^2.3^{20}.\left(2^3\right)^9}{5.2^2.\left(3.2\right)^{19}-7.2^{29}.\left(3^3\right)^6}\)

\(=\dfrac{5.2^{30}.3^{18}-2^2.2^{27}.3^{20}}{5.2^2.2^{19}.3^{19}-7.2^{29}.3^{18}}\)

\(=\dfrac{5.2^{30}.3^{18}-2^{29}.3^{20}}{5.2^{28}.3^{19}-7.2^{29}.3^{18}}\)

\(=\dfrac{2^{29}.3^{18}.\left(5.2-3\right)}{2^{28}.3^{18}.\left(5.1.3-7.2.1\right)}\)

\(=\dfrac{2^{29}.3^{18}.1}{2^{28}.3^{18}.1}\)

\(=\dfrac{2^{29}}{2^{28}}\)

\(=2\)

nga nguyem CHẬP MẠCH rồi

\(\frac{5\times4^{15}\times9^9-4\times3^{20}\times8^9}{5\times2^9\times6^{19}-7\times2^{29}\times27^6}\)

\(=\frac{5\times\left(2^2\right)^{15}\times\left(3^2\right)^9-2^2\times3^{20}\times\left(2^3\right)^9}{5\times2^9\times\left(2\times3\right)^{19}-7\times2^{29}\times\left(3^3\right)^6}\)

\(=\frac{5\times2^{30}\times3^{18}-2^2\times3^{20}\times3^{27}}{5\times2^9\times2^{19}\times3^{19}-7\times2^{29}\times3^{18}}\)

\(=\frac{2^{29}\times3^{18}\times\left(5\times2-3^2\right)}{2^{28}\times3^{18}\times\left(5\times3-7\times2\right)}\)

\(=2\)

Chúc bạn học tốt ^^

thanks

Xét tử :

5.4¹⁵.9⁹ - 4.3²⁰.8⁹

= 5.2³⁰.3¹⁸ - 2² . 3²⁰ . 2²⁷

= 5 . 2³⁰ . 3¹⁸ - 2²⁹ . 3²⁰

= 3¹⁸ . 2²⁰ . ( 5 . 2¹⁰ - 2⁹ . 3² )

= 3¹⁸ . 2²⁰ . [ 2⁹ . ( 5 . 2 - 3² ) ]

= 3¹⁸ . 2²⁰ . 2⁹

= 3¹⁸ . 2²⁹

Xét mẫu :

5.2⁹.6¹⁹ - 7.2²⁹.27⁶

= 5 . 2⁹ . 2¹⁹ . 3¹⁹ - 7 . 2²⁹ . 3¹⁸

= 5 . 2²⁸ . 3¹⁹ - 7 . 2²⁹ . 3¹⁸

= 3¹⁸ . 2²⁸ . ( 5 . 3 - 7 . 2 )

= 3¹⁸ . 2²⁸

B = \(\frac{3^{18}.2^{29}}{3^{18}.2^{28}}=2\)

\(\dfrac{5.4^{15}.9^9-4.3^{20}.8^9}{5.2^9.6^{19}-7.2^{29}.27^6}\)

\(=\dfrac{5.3^{20}.3^{18}-2^2.2^{27}.3^{20}}{5.2^9.2^{19}.3^{19}-7.2^{29}.3^{18}}\)

\(=\dfrac{2^{29}.3^{18}\left(5.2-3^2\right)}{2^{28}.3^{18}\left(5.3-7.2\right)}\)

\(=2\)