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9 tháng 2 2017

vgcsdhvGe

A. 2.9 +6 -4 = 20

B. 8.25 - 6.9 + (-12) = 134

C. -962 + 1548 = 586

D. -85.(36+54) = -85 x 100 = -8500

F. 26.37 - 26.56 - 56.37 + 56.26 =26.37 - 56.37 = 37.(26 - 56)

=37. (-30) = -1100

E. 130 - ( 27 - (36 + 128).2))3

= 130 - ( 27 - 328).3

= 130 - (-301).3

= 130 - (-903)

= 1033

6 tháng 1 2023

Khóc

 

`#3107`

b)

`2.3^x = 162`

`\Rightarrow 3^x = 162 \div 2`

`\Rightarrow 3^x = 81`

`\Rightarrow 3^x = 3^4`

`\Rightarrow x = 4`

Vậy, `x = 4`

c)

`(2x - 15)^5 = (2 - 15)^3`

\(\Rightarrow \)`(2x - 15)^5 - (2x - 15)^3 = 0`

\(\Rightarrow \)`(2x - 15)^3 . [ (2x - 15)^2 - 1] = 0`

\(\Rightarrow\left[{}\begin{matrix}\left(2x-15\right)^3=0\\\left(2x-15\right)^2-1=0\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}2x-15=0\\\left(2x-15\right)^2=1\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}2x=15\\\left(2x-15\right)^2=\left(\pm1\right)^2\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=\dfrac{15}{2}\\2x-15=1\\2x-15=-1\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=\dfrac{15}{2}\\2x=16\\2x=-14\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=\dfrac{15}{2}\\x=8\\x=-7\end{matrix}\right.\)

Vậy, `x \in`\(\left\{-7;8;\dfrac{15}{2}\right\}.\)

`d)`

\(3^{x+2}-5.3^x=?\) Bạn ghi tiếp đề nhé!

`e)`

\(7\cdot4^{x-1}+4^{x-1}=23?\)

\(4^{x-1}\cdot\left(7+1\right)=23\\ \Rightarrow4^{x-1}\cdot8=23\\ \Rightarrow4^{x-1}=\dfrac{23}{8}\)

Bạn xem lại đề!

`f)`

\(2\cdot2^{2x}+4^3\cdot4^x=1056\)

\(\Rightarrow2\cdot2^{2x}+\left(2^2\right)^3\cdot\left(2^2\right)^x=1056\\ \Rightarrow2\cdot2^{2x}+2^6\cdot2^{2x}=1056\\ \Rightarrow2^{2x}\cdot\left(2+2^6\right)=1056\\ \Rightarrow2^{2x}\cdot66=1056\\ \Rightarrow2^{2x}=1056\div66\\ \Rightarrow2^{2x}=16\\ \Rightarrow2^{2x}=2^4\\ \Rightarrow2x=4\\ \Rightarrow x=2\)

Vậy, `x = 2`

_____

\(10 -{[(x \div 3+17) \div 10+3.2^4] \div 10}=5\)

\(\Rightarrow\left[\left(x\div3+17\right)\div10+48\right]\div10=10-5\)

\(\Rightarrow\left[\left(x\div3+17\right)\div10+48\right]\div10=5\)

\(\Rightarrow\left(x\div3+17\right)\div10+48=50\)

\(\Rightarrow\left(x\div3+17\right)\div10=2\)

\(\Rightarrow x\div3+17=20\)

\(\Rightarrow x\div3=3\\ \Rightarrow x=9\)

Vậy, `x = 9.`

27 tháng 6 2017

\(M=\frac{9^4.27^5.3^6.3^4}{3^8.81^4.234.8^2}=\frac{\left(3^2\right)^4.\left(3^3\right)^5.3^6.3^4}{3^8.\left(3^4\right)^4.3^5.\left(2^3\right)^2}\)

\(M=\frac{3^8.3^{15}.3^6.3^4}{3^{18}.3^{16}.3^5.2^6}=\frac{81}{64}\)

\(N=\frac{4^6.9^5.6^9.120}{8^4.3^{12}-6^{11}}=\frac{2^{12}.3^{10}+2^{12}.3^{10}.5}{2^{12}.3^{12}-2^{11}.3^{11}}\)

\(N=\frac{2^{12}.3^{10}.\left(1+5\right)}{2^{11}.3^{11}.\left(2.3-1\right)}=\frac{2.6}{3.5}\)

\(N=\frac{4}{5}\)

17 tháng 8 2023

1. a) 40

    b) 3

    c) 18

    d) 3

2. a) 291

    b) 37

    c) 61

    d) 284

9 tháng 7 2017

\(\dfrac{7.4^5.3^{11}+2^{13}.9^5}{6^{10}+2^{12}.3^{10}}\) \(=\dfrac{7.\left(2^2\right)^5+2^{13}.\left(3^3\right)^5}{\left(2.3\right)^{10}+2^{12}.3^{10}}\) \(=\dfrac{7.2^{10}.3^{11}+2^{13}.3^{15}}{2^{10}.3^{10}+2^{12}.3^{10}}\)

\(=\dfrac{7.2^{10}.3^{10}.3+2^{10}.2^3.3^{10}.3^5}{2^{10}.3^{10}+2^{10}.2^2.3^{10}}\) \(=\dfrac{2^{10}.3^{10}\left(7.3+2^3.3^5\right)}{2^{10}.3^{10}\left(1+2^2\right)}\)

\(=\dfrac{7.3+2^3.3^5}{1+2^2}\) \(=\dfrac{21+8.243}{5}\) \(=\dfrac{1965}{5}=393\)

9 tháng 7 2017

\(\dfrac{7.4^5.3^{11}+2^{13}.9^5}{6^{11}+2^{12}.3^{10}}\)=\(\dfrac{7.\left(2^2\right)^5.3^{11}+2^{13}.\left(3^2\right)^5}{\left(2.3\right)^{11}+2^{12}.3^{11}}\)=\(\dfrac{7.2^{10}.3^{11}+2^{13}.3^{10}}{2^{11}.3^{11}+2^{12}.3^{11}}\)

= \(\dfrac{3^{10}.\left(7.3.2^{10}+2^{13}\right)}{3^{11}.\left(2^{11}+2^{12}\right)}\)=\(\dfrac{3^{10}.\left(21.2^{10}+2^{13}\right)}{3^{11}.\left(2^{11}+2^{12}\right)}\)=\(\dfrac{21.2^{10}+2^{13}}{3.\left(2^{11}+2^{12}\right)}\)

10 tháng 1 2016

\(\frac{7.4^5.3^{11}+2^{13}.9^5}{6^{10}+2^{12}.3^{10}}=\frac{7.\left(2^2\right)^5.3^{11}+2^{13}.\left(3^2\right)^5}{\left(2.3\right)^{10}+2^{12}.3^{10}}=\frac{7.2^{10}.3^{11}+2^{13}.3^{10}}{2^{10}.3^{10}+2^{12}.3^{10}}\)

\(=\frac{2^{10}.3^{10}.\left(7.3+2^3\right)}{2^{10}.3^{10}.\left(1+2^2\right)}=\frac{7.3+2^3}{1+2^2}=\frac{29}{5}\)