Question

Rút gọn biểu thức 

a) \(\frac{2^7.9^3}{6^5.8^2}\)             b) \(\frac{6^3+3.6^2+3^3}{-13}\)             c) \(\frac{5^4.20^4}{25^5.4^5}\)

3 tick nha mn 

Answer 1

\(a,=\frac{2^7\cdot\left(3^2\right)^3}{2^5\cdot3^5\cdot2^3}=\frac{2^7\cdot3^6}{2^8\cdot3^5}=\frac{3}{2}\)

Answer 2

câu a)

\(=\frac{2^7\times\left(3^2\right)^3}{2^5\times3^5\times2^3}=\frac{2^7\times3^6}{2^8\times3^5}=\frac{3}{2}\)

Answer 3

Bài làm

a) \(\frac{2^7.9^3}{6^5.8^2}=\frac{2^7.\left(3^2\right)^3}{\left(2.3\right)^5.\left(2^3\right)^2}=\frac{2^7.3^5}{2^5.3^5.2^5}=\frac{1.1}{1.1.2^3}=\frac{1}{2^3}=\frac{1}{8}\)

b) \(\frac{6^3+3.6^2+3^3}{-13}=\frac{6^2.6+3.6^2+3^3}{-13}=\frac{6^2.\left(6+3+3^3\right)}{-13}=\frac{36.36}{-13}\approx-99,7\)

c) \(\frac{5^4.20^4}{25^5.4^5}=\frac{5^4.\left(4.5\right)^4}{\left(5^2\right)^5.4^5}=\frac{5^4.4^4.5^4}{5^7.4^7}=\frac{5.1.1}{1.4^3}=\frac{5}{64}\approx0,08\)

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Answer 4

b,

( 6^3 + 3x6^2 + 3^3)/( -13) = -27

c,

( 5^4 x 20^4) / ( 25^5 x 4^5 )

=( 5^4 x 5^4 x 4^4 )/ ( 5^5 x 5^5 x 4^5) = 1/ 5x5x4 = 1/100

Answer 5

\(\frac{2^7.9^3}{6^5.8^2}=\frac{2^7.\left(3^2\right)^3}{2^5.3^5.\left(2^3\right)^2}=\frac{2^7.3^6}{2^5.2^6.3^5}=\frac{2^7.3^6}{2^{11}.3^5}=\frac{3}{2^4}\)

\(\frac{6^3+3.6^2+3^3}{-13}=\frac{3^3.2^3+3.3^2.2^2+3^3}{-13}=\frac{3^3.\left(2^3+2^2+1\right)}{-13}=\frac{3^3.13}{-13}=-3^3\)

\(\frac{5^4.20^4}{25^5.4^5}=\frac{5^4.4^4.5^4}{\left(5^2\right)^5.4^5}=\frac{5^8.4^4}{5^{10}.4^5}=\frac{1}{5^2.4}=\frac{1}{100}\)