A)\(-6.(-\frac{2}{3}).0,25\) B) \(-\frac{15}{4}.(\frac{-7}{15}).(-2\frac{2}{5})\) C) \(\left(-0,4\right)^2-\left(-0,4\right)^3.\left(-3\right)\) D) \(\left[\left(-2,7\right)^4\right]^5-\left[\left(-2,...

3

NB

Ngô Bá Hùng

17 tháng 9 2019

Dat thế cái máy tính để làm gì hả bác????

VM

Vũ Minh Tuấn

17 tháng 9 2019

a) \(-6.\left(-\frac{2}{3}\right).0,25\)

\(=-6.\left(-\frac{2}{3}\right).\frac{1}{4}\)

\(=4.\frac{1}{4}\)

\(=1.\)

b) \(-\frac{15}{4}.\left(-\frac{7}{15}\right).\left(-2\frac{2}{5}\right)\)

\(=-\frac{15}{4}.\left(-\frac{7}{15}\right).\left(-\frac{12}{5}\right)\)

\(=\frac{7}{4}.\left(-\frac{12}{5}\right)\)

\(=-\frac{21}{5}.\)

c) \(\left(-0,4\right)^2-\left(-0,4\right)^3.\left(-3\right)\)

\(=0,16-\left(-0,064\right).\left(-3\right)\)

\(=0,16-0,192\)

\(=-0,032.\)

Chúc bạn học tốt!

Tính:a)\(0,75 - \frac{5}{6} + 1\frac{1}{2};\) b)\(\frac{3}{7} + \frac{4}{{15}} + \left( {\frac{{ - 8}}{{21}}} \right) + \left( { - 0,4} \right);\)c)\(0,625 + \left( {\frac{{ - 2}}{7}} \right) + \frac{3}{8} + \left( {\frac{{ - 5}}{7}} \right) + 1\frac{2}{3}\) d)\(\left( { - 3} \right).\left( {\frac{{ - 38}}{{21}}} \right).\left( {\frac{{ - 7}}{6}} \right).\left( { - \frac{3}{{19}}} \right);\)e) \(\left( {\frac{{11}}{{18}}:\frac{{22}}{9}}...

QT

Quoc Tran Anh Le

Giáo viên

19 tháng 9 2023

1

HQ

Hà Quang Minh

Giáo viên

19 tháng 9 2023

a)

\(\begin{array}{l}0,75 - \frac{5}{6} + 1\frac{1}{2} = \frac{3}{4} - \frac{5}{6} + \frac{3}{2}\\ = \frac{9}{{12}} - \frac{{10}}{{12}} + \frac{{18}}{{12}} = \frac{{17}}{{12}}\end{array}\)

b)

\(\begin{array}{l}\frac{3}{7} + \frac{4}{{15}} + \left( {\frac{{ - 8}}{{21}}} \right) + \left( { - 0,4} \right) = \frac{3}{7} + \frac{4}{{15}} - \frac{8}{{21}} - \frac{2}{5}\\ = \left( {\frac{3}{7} - \frac{8}{{21}}} \right) + \left( {\frac{4}{{15}} - \frac{2}{5}} \right)\\ = \left( {\frac{9}{{21}} - \frac{8}{{21}}} \right) + \left( {\frac{4}{{15}} - \frac{6}{{15}}} \right)\\ = \frac{1}{{21}} + \left( {\frac{{ - 2}}{{15}}} \right)\\ = \frac{5}{{105}} - \frac{{14}}{{105}}\\ = \frac{{ - 9}}{{105}} = \frac{{ - 3}}{{35}}\end{array}\)

c)

\(\begin{array}{l}0,625 + \left( {\frac{{ - 2}}{7}} \right) + \frac{3}{8} + \left( {\frac{{ - 5}}{7}} \right) + 1\frac{2}{3}\\ = \frac{5}{8} + \left( {\frac{{ - 2}}{7}} \right) + \frac{3}{8} - \frac{5}{7} + \frac{5}{3}\\ = \left( {\frac{5}{8} + \frac{3}{8}} \right) + \left( {\frac{{ - 2}}{7} - \frac{5}{7}} \right) + \frac{5}{3}\\ = 1 - 1 + \frac{5}{3} = \frac{5}{3}\end{array}\)

d)

\(\begin{array}{l}\left( { - 3} \right).\left( {\frac{{ - 38}}{{21}}} \right).\left( {\frac{{ - 7}}{6}} \right).\left( { - \frac{3}{{19}}} \right)\\ = \frac{{ - 3.\left( { - 38} \right).\left( { - 7} \right).\left( { - 3} \right)}}{{21.6.19}}\\ = \frac{{3.38.7.3}}{{21.6.19}}\\ = \frac{{3.2.19.7.3}}{{3.7.3.2.19}}\\ = 1\end{array}\)

e)

\(\begin{array}{l}\left( {\frac{{11}}{{18}}:\frac{{22}}{9}} \right).\frac{8}{5} = \left( {\frac{{11}}{{18}}.\frac{9}{{22}}} \right).\frac{8}{5}\\ = \frac{{11.9.4.2}}{{9.2.2.11.5}} = \frac{2}{5}\end{array}\)

g)

\(\left[ {\left( {\frac{{ - 4}}{5}} \right).\frac{5}{8}} \right]:\left( {\frac{{ - 25}}{{12}}} \right) = \frac{{ - 20}}{{40}}:\left( {\frac{{ - 25}}{{12}}} \right)\\ = \frac{{ - 1}}{2}.\frac{{ - 12}}{{25}} = \frac{6}{{25}}\)

DD

Đỗ Diệu Linh

12 tháng 2 2017

Rút...

1

NL

Nguyễn Lê Phước Thịnh

12 tháng 5 2022

2: \(=\dfrac{0.8}{\dfrac{16}{25}-\dfrac{1}{25}}+\dfrac{\dfrac{71}{75}\cdot\dfrac{7}{4}}{\dfrac{119}{36}\cdot\dfrac{36}{17}}\)

\(=\dfrac{4}{5}\cdot\dfrac{5}{3}+\dfrac{71}{300}=\dfrac{471}{300}=\dfrac{157}{100}\)

3: \(=\dfrac{\dfrac{2}{5}-\dfrac{2}{9}+\dfrac{2}{11}}{\dfrac{7}{5}-\dfrac{7}{9}+\dfrac{7}{11}}-\dfrac{\dfrac{2}{6}-\dfrac{2}{8}+\dfrac{2}{10}}{\dfrac{7}{6}-\dfrac{7}{8}+\dfrac{7}{10}}\)

=2/7-2/7=0

HM

Hasune Miku

1 tháng 2 2017

Tính :

a) \(1\frac{7}{20}:2,7+2,7:1,35+\left(0,4:2\frac{1}{2}\right).\left(4,8-1\frac{3}{40}\right)\)

b) \(\left[\left(6\frac{3}{5}-3\frac{3}{14}\right):5\frac{5}{6}\right]:\left[\left(21-1,25\right):2,5\right]\)

0

PQ

Phí Quỳnh Anh

14 tháng 7 2016

...

\(a,1\frac{13}{15}.0,75-\left(\frac{8}{15}+0,25\right).\frac{24}{47}\) \(b,5:\left(4\frac{3}{4}-1\frac{25}{28}\right)-1\frac{3}{8}:\left(\frac{3}{8}+\frac{9}{20}\right)\) \(c,6\frac{5}{12}:2\frac{3}{4}+11\frac{1}{4}.\left(\frac{1}{3}-\frac{1}{5}\right)\) \(d,\left(\frac{3}{5}+0,415-\frac{3}{200}\right).2\frac{2}{3}.0,25\) \(e,\left(\frac{3}{8}+\frac{-3}{4}+\frac{7}{12}\right):\frac{5}{6}+\frac{1}{2}\) \(g,1\frac{13}{15}.0,75-\left(\frac{11}{20}+25\%\right);\frac{7}{3}\) ...

0

PN

Phạm Ninh Đan

1 tháng 8 2020

BÀi 1: Thực hiện phép tính ( tính nhanh nếu có...

0

HT

Huỳnh Thị Thu Uyên

25 tháng 7 2016

0

LN

le nguyen hien anh

1 tháng 2 2020

...

1

HM

Hoàng Minh Chi

1 tháng 2 2020

\(A=\frac{15}{34}+\frac{7}{21}+\frac{9}{34}-1\frac{15}{17}+\frac{2}{3}=\frac{15}{34}+\frac{7}{21}+\frac{9}{34}-\frac{64}{34}+\frac{14}{21}=\left(\frac{15}{34}+\frac{9}{34}-\frac{64}{34}\right)+\left(\frac{7}{21}+\frac{14}{21}\right)=\frac{30}{34}+\frac{21}{21}=\frac{15}{17}+1=\frac{32}{17}\)

QT

Quoc Tran Anh Le

Giáo viên

19 tháng 9 2023

Tính:

a)\({\left( { - 2} \right)^2}.{\left( { - 2} \right)^3}\); b)\({\left( { - 0,25} \right)^7}:{\left( { - 0,25} \right)^5}\); c)\({\left( {\frac{3}{4}} \right)^4}.{\left( {\frac{3}{4}} \right)^3}.\)

1

HQ

Hà Quang Minh

Giáo viên

19 tháng 9 2023

a)\({\left( { - 2} \right)^2}.{\left( { - 2} \right)^3} = {\left( { - 2} \right)^{2 + 3}} = {\left( { - 2} \right)^5}\);

b)\({\left( { - 0,25} \right)^7}:{\left( { - 0,25} \right)^5} = {\left( { - 0,25} \right)^{7 - 5}} = {\left( { - 0,25} \right)^2} = {\left( {0,25} \right)^2}\);

c)\({\left( {\frac{3}{4}} \right)^4}.{\left( {\frac{3}{4}} \right)^3} = {\left( {\frac{3}{4}} \right)^{4 + 3}} = {\left( {\frac{3}{4}} \right)^7}.\)

S

Sagittarus

5 tháng 1 2016

tìm x,y...