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22 tháng 4 2021

=44/15

ok chưa

19 tháng 9 2016

\(A=\frac{2^{12}.3^5-4^6.9^2}{\left(2^2.3\right)^6+8^4.3^5}-\frac{5^{10}.7^3-25^5.49^2}{\left(125.7\right)^3+5^9.14^3}\)

\(\Rightarrow A=\frac{2^{12}.3^5-\left(2^2\right)^6.\left(3^2\right)^2}{2^{12}.3^6+\left(2^3\right)^4.3^5}-\frac{5^{10}.7^3-\left(5^2\right)^5.\left(7^2\right)^2}{\left(5^3.7\right)^3+5^9.\left(2.7\right)^3}\)

\(\Rightarrow A=\frac{2^{12}.3^5-2^{12}.3^4}{2^{12}.3^6+2^{12}.3^5}-\frac{5^{10}.7^3-5^{10}.7^4}{5^9.7^3+5^9.7^3.2^3}\)

\(\Rightarrow A=\frac{2^{12}.3^4\left(3-1\right)}{2^{12}.3^5\left(3+1\right)}-\frac{5^{10}.7^3\left(1-4\right)}{5^9.7^8\left(1+2^3\right)}\)

\(\Rightarrow A=\frac{2}{3.4}-\frac{5.\left(-3\right)}{9}\)

\(\Rightarrow A=\frac{1}{3}-\frac{-15}{9}\)

\(\Rightarrow A=\frac{1}{3}+\frac{5}{3}\)

\(\Rightarrow A=\frac{6}{3}=2\)

Vậy \(A=2\)

24 tháng 8 2015

a=2^12.3^5-2^12.3^4/2^12.3^6+2^12.3^5 - 5^10.7^3-5^10.7^4/5^9.7^3+5^9.7^3.2^3

a=2^12.3^4.(3-1)/2^12.3^5.(3+1)-5^10.7^3.(1-7)/5^9.7^3.(1+8)

a=2/12-30/9

a=1/6-10/3=-19/6

a=

20 tháng 4 2016

=2^12.3^5-2^12.3^4/2^12.3^6+2^12.3^5 - 5^10.7^3-5^10.7^4/5^9.7^3+5^9.7^3.2^3

=2^12.3^4.(3-1)/2^12.3^5.(3+1) - 5^10.7^3.(1-7)/5^9.7^3.(1+2^3)

=3-1/3.(3+1) - 5.(1-7)/1+2^3

=2/12 + 30/9 = 1/6 + 10/3 = 7/2

HQ
Hà Quang Minh
Giáo viên
8 tháng 10 2023

a)

\(\begin{array}{l}\frac{2}{3} + \frac{{ - 2}}{5} + \frac{{ - 5}}{6} - \frac{{13}}{{10}}\\ = \frac{2}{3} + \frac{{ - 5}}{6} + \frac{{ - 2}}{5} - \frac{{13}}{{10}}\\ = \left( {\frac{2}{3} + \frac{{ - 5}}{6}} \right) + \left( {\frac{{ - 2}}{5} - \frac{{13}}{{10}}} \right)\\ = \left( {\frac{4}{6} + \frac{{ - 5}}{6}} \right) + \left( {\frac{{ - 4}}{{10}} - \frac{{13}}{{10}}} \right)\\ = \frac{{ - 1}}{6} + \frac{{ - 17}}{{10}}\\ = \frac{{ - 5}}{{30}} + \frac{{ - 51}}{{30}}\\ = \frac{{ - 56}}{{30}}\\ = \frac{{ - 28}}{{15}}\end{array}\)

b)

\(\begin{array}{l}\frac{{ - 3}}{7}.\frac{{ - 1}}{9} + \frac{7}{{ - 18}}.\frac{{ - 3}}{7} + \frac{5}{6}.\frac{{ - 3}}{7}\\ = \frac{{ - 3}}{7}.\left( {\frac{{ - 1}}{9} + \frac{7}{{ - 18}} + \frac{5}{6}} \right)\\ = \frac{{ - 3}}{7}.\left( {\frac{{ - 2}}{{18}} + \frac{{ - 7}}{{18}} + \frac{{15}}{{18}}} \right)\\ = \frac{{ - 3}}{7}.\frac{{ 6}}{{18}}\\ = \frac{-1}{7}\end{array}\).

HQ
Hà Quang Minh
Giáo viên
8 tháng 10 2023

a) Với \(\frac{m}{n} = \frac{{ - 5}}{6}\), giá trị của biểu thức là:

\(\begin{array}{l}A = \frac{{ - 2}}{3} - \left( {\frac{{ - 5}}{6} + \frac{{ - 5}}{2}} \right).\frac{{ - 5}}{8}\\A = \frac{{ - 2}}{3} - \frac{{-20}}{6}.\frac{{ - 5}}{8}\\A = \frac{{ - 2}}{3} - \frac{{ 25}}{{12}}\\A = \frac{{ - 33}}{{12}}\end{array}\)

b) Với \(\frac{m}{n} = \frac{5}{2}\) , giá trị của biểu thức là:

\(\begin{array}{l}A = \frac{{ - 2}}{3} - \left( {\frac{5}{2} + \frac{{ - 5}}{2}} \right).\frac{{ - 5}}{8}\\A = \frac{{ - 2}}{3} - 0.\frac{{ - 5}}{8} = \frac{{ - 2}}{3}\end{array}\)

c) Với \(\frac{m}{n} = \frac{2}{{ - 5}}\) , giá trị của biểu thức là:

\(\begin{array}{l}A = \frac{-2}{3} - \left( {\frac{2}{{ - 5}} + \frac{{ - 5}}{2}} \right).\frac{{ - 5}}{8}\\A = \frac{-2}{3} - \left( {\frac{{ - 4}}{{10}} + \frac{{ - 25}}{{10}}} \right).\frac{{ - 5}}{8}\\A = \frac{-2}{3} - \frac{{ - 29}}{{10}}.\frac{{ - 5}}{8}\\A = \frac{-2}{3} - \frac{{29}}{{16}}\\A = \frac{{-32}}{{48}} - \frac{{87}}{{48}}\\A = \frac{{ - 119}}{{48}}\end{array}\).

15 tháng 7 2017

\(\frac{2^{12}.3^5-4^6.9^2}{\left(2^2.3\right)^6+8^4.3^5}-\frac{5^{10}.7^3-25^5.49^2}{\left(125.7\right)^3+5^9.14^3}\)

\(=\frac{2^{12}.3^5-\left(2^2\right)^6.\left(3^2\right)^2}{2^{12}.3^6+\left(2^3\right)^4.3^5}-\frac{5^{10}.7^3-\left(5^2\right)^5.\left(7^2\right)^2}{\left(5^3.7\right)^3+5^9.\left(2.7\right)^3}\)

\(=\frac{2^{12}.3^5-2^{12}.3^4}{2^{12}.3^6+2^{12}.3^5}-\frac{5^{10}.7^3-5^{10}.7^4}{5^9.7^3+5^9.2^3.7^3}\)

\(=\frac{2^{12}.3^4\left(3-1\right)}{2^{12}.3^5\left(3+1\right)}-\frac{5^{10}.7^3.\left(1-7\right)}{5^9.7^3\left(1+2^3\right)}\)

\(=\frac{2^{12}.3^4.2}{2^{12}.3^5.4}-\frac{5^{10}.7^3.\left(-6\right)}{5^9.7^3.9}\)

\(=\frac{1}{6}-\frac{-10}{3}=\frac{1}{6}+\frac{10}{3}=\frac{1}{6}+\frac{20}{6}=\frac{21}{6}=\frac{7}{2}\)

9 tháng 1 2018

lam nhu stctv ay dung day to thu lam roi

23 tháng 7 2016

c=39/64

d=913/105

23 tháng 7 2016

3) C thiếu đề

4) \(D=\frac{1}{9}-\left|\frac{-5}{23}\right|-\left(\frac{-5}{23}+\frac{1}{9}+\frac{25}{7}\right)+\frac{50}{4}-\frac{7}{30}\)

\(D=\frac{1}{9}-\frac{5}{23}+\frac{5}{23}-\frac{1}{9}-\frac{25}{7}+\frac{50}{4}-\frac{7}{30}\)

\(D=\frac{1}{9}-\frac{1}{9}-\frac{5}{23}+\frac{5}{23}+\frac{-25}{7}+\frac{50}{4}-\frac{7}{30}\)

\(D=0+0+\frac{125}{14}-\frac{7}{30}\)

\(D=\frac{913}{105}\)

15 tháng 7 2017

\(A=\frac{25^3.5^5}{6.5^{10}}\)

\(A=\frac{\left(5^2\right)^3.5^5}{6.5^{10}}\)

\(A=\frac{5^6.5^5}{6.5^{10}}\)

\(A=\frac{5^{11}}{6.5^{10}}\)

\(A=\frac{5}{6}\)

(Dùng phương pháp giảm ước)

15 tháng 7 2017

\(=\frac{\left(5^2\right)^3.5^5}{6.5^{10}}\)

\(=\frac{5^6.5^5}{6.5^{10}}\)

\(=\frac{5^{11}}{6.5^{10}}\)

\(=\frac{5}{6}\)

VẬY \(A=\frac{5}{6}\)