Bạn chưa đăng nhập. Vui lòng đăng nhập để hỏi bài

Những câu hỏi liên quan
Nguyễn Ngọc Thiên Trang
Xem chi tiết
Ngân Hoàng Xuân
28 tháng 6 2016 lúc 10:48

a) \(\left(\frac{1}{3}-\frac{1}{5}\right)^2:\left(\frac{1}{5}\right)^2=\left[\left(\frac{1}{3}-\frac{1}{5}\right):\frac{1}{5}\right]^2=\left(\frac{2}{15}:\frac{1}{5}\right)^2=\left(\frac{2}{3}\right)^2=\frac{4}{9}\)

 

Ngân Hoàng Xuân
28 tháng 6 2016 lúc 10:52

c)\(7\frac{1}{23}+\frac{10}{27}-5\frac{1}{23}+\frac{17}{27}+2^3=\left(7\frac{1}{23}-5\frac{1}{23}\right)+\left(\frac{10}{27}+\frac{17}{27}\right)+2^3=2+1+8=11\)

d)\(5.\left(-\frac{5}{2}\right)^2+\frac{1}{5}.\left(-3\right)^2=5.\frac{25}{4}+\frac{1}{5}.9=\frac{125}{4}+\frac{9}{5}=\frac{661}{20}\)

Ngọc Mai
28 tháng 6 2016 lúc 11:02

a)  \(\left(\frac{1}{3}-\frac{1}{5}\right)^2:\left(\frac{1}{5}\right)^2=\left[\left(\frac{1}{3}-\frac{1}{5}\right):\frac{1}{5}\right]^2=\left[\left(\frac{5}{15}-\frac{3}{15}\right):\frac{1}{5}\right]^2=\left[\frac{2}{15}.5\right]^2=\left[\frac{2}{3}\right]^2=\frac{4}{9}\)

b) \(\frac{2^3.5^2.8}{10^{10}}=\frac{2^3.5^2.2^3}{\left(2.5\right)^{10}}=\frac{\left(2^3.2^3\right).5^2}{2^{10}.5^{10}}=\frac{2^6.5^2}{2^{10}.5^{10}}=\frac{1}{2^4.5^8}=\frac{1}{6250000}\)

c) \(7\frac{1}{23}+\frac{10}{27}-5\frac{1}{23}+\frac{17}{27}+2^3\)

\(=\left(7\frac{1}{23}-5\frac{1}{23}\right)+\left(\frac{10}{27}+\frac{17}{27}\right)+2^3\)

\(=2+1+8\)

\(=11\)

d) \(5.\left(-\frac{5}{2}\right)^2+\frac{1}{5}.\left(-3\right)^2\)

\(=5.\frac{25}{4}+\frac{1}{5}.9\)

\(=\frac{125}{4}+\frac{9}{5}\)

\(=\frac{625}{20}+\frac{36}{20}=\frac{661}{20}\)

Chuk bạn hok tốt ! vui

Olivia
Xem chi tiết
thái quang phong
19 tháng 3 2020 lúc 11:26

a) \(\frac{-1}{24}-\left[\frac{1}{4}-\left(\frac{1}{2}-\frac{7}{8}\right)\right]\)

= \(\frac{-1}{24}-\left[\frac{6}{24}-\left(\frac{12}{24}-\frac{21}{24}\right)\right]\)

= \(\frac{-1}{24}-\left[\frac{6}{24}-\frac{-9}{24}\right]\)

= \(\frac{-1}{24}-\frac{15}{24}\)

= \(\frac{-16}{24}\) = \(\frac{-2}{3}\)

Khách vãng lai đã xóa
thái quang phong
19 tháng 3 2020 lúc 11:55

b) \(\left(\frac{5}{7}-\frac{7}{5}\right)-\left[\frac{1}{2}-\left(-\frac{2}{7}-\frac{1}{10}\right)\right]\)

= \(\left(\frac{50}{70}-\frac{98}{70}\right)-\left[\frac{35}{70}-\left(-\frac{20}{70}-\frac{7}{70}\right)\right]\)

= \(\frac{-48}{70}-\left[\frac{35}{70}-\left(-\frac{20}{70}-\frac{7}{70}\right)\right]\)

= \(\frac{-48}{70}-\left[\frac{35}{70}-\frac{-27}{70}\right]\)

= \(\frac{-48}{70}-\frac{62}{70}\)

= \(\frac{-110}{70}=\frac{-11}{7}\)

Khách vãng lai đã xóa
thái quang phong
19 tháng 3 2020 lúc 12:19

c) \(\left(-\frac{1}{2}\right)-\left(-\frac{3}{5}\right)+\left(-\frac{1}{9}\right)+\frac{1}{17}-\left(-\frac{2}{7}\right)+\frac{4}{35}-\frac{7}{18}\)

= \(\frac{-1}{2}+\frac{3}{5}+\frac{-1}{9}+\frac{1}{17}+\frac{2}{7}+\frac{4}{35}-\frac{7}{18}\)

= \(\left(\frac{-1}{2}+\frac{-1}{9}-\frac{7}{18}\right)+\left(\frac{3}{5}+\frac{2}{7}+\frac{4}{35}\right)+\frac{1}{17}\)

= \(\left(\frac{-9}{18}+\frac{-2}{18}-\frac{7}{18}\right)+\left(\frac{21}{35}+\frac{10}{35}+\frac{4}{35}\right)+\frac{1}{17}\)

= \(-1+1+\frac{1}{17}\)

= \(0+\frac{1}{17}=\frac{1}{17}\)

CHÚC BẠN HỌC TỐT (^_^) !!!!!!!!!!

Khách vãng lai đã xóa
tài khoản mới
Xem chi tiết
Nhi Nguyễn
Xem chi tiết
Nguyễn Lê Phước Thịnh
28 tháng 6 2022 lúc 9:54

Bài 1: 

\(\Leftrightarrow-\dfrac{5}{7}:x=-\dfrac{7}{18}-\dfrac{1}{6}=\dfrac{-7}{18}-\dfrac{3}{18}=\dfrac{-10}{18}=\dfrac{-5}{9}\)

=>x=5/9:5/7=7/9

Bài 2:

a: \(=\dfrac{3}{2}\cdot\dfrac{4}{3}\cdot...\cdot\dfrac{1000}{999}=\dfrac{1000}{2}=500\)

b: \(=\dfrac{-1}{2}\cdot\dfrac{-2}{3}\cdot...\cdot\dfrac{-999}{1000}\)

\(=-\dfrac{1}{1000}\)

Nguyen Ngoc Lien
Xem chi tiết
Lightning Farron
13 tháng 10 2016 lúc 18:41

bn đăng từng câu 1 thôi nhe

 

Nguyễn Châu Mỹ Linh
Xem chi tiết
Lê Thanh Thúy
Xem chi tiết
Akai Haruma
23 tháng 12 2019 lúc 10:44

Bài 2:

a)

\(\frac{2}{3}-(\frac{3}{4}-x)=\sqrt{\frac{1}{9}}=\frac{1}{3}\)

\(\frac{3}{4}-x=\frac{2}{3}-\frac{1}{3}=\frac{1}{3}\)

\(x=\frac{3}{4}-\frac{1}{3}=\frac{5}{12}\)

b)

\((\frac{1}{2}-x)^2=(-2)^2=2^2\)

\(\Rightarrow \left[\begin{matrix} \frac{1}{2}-x=-2\\ \frac{1}{2}-x=2\end{matrix}\right.\Rightarrow \left[\begin{matrix} x=\frac{5}{2}\\ x=\frac{-3}{2}\end{matrix}\right.\)

c)

\(|3x+\frac{1}{2}|-\frac{2}{3}=1\)

\(|3x+\frac{1}{2}|=\frac{2}{3}+1=\frac{5}{3}\)

\(\Rightarrow \left[\begin{matrix} 3x+\frac{1}{2}=\frac{5}{3}\\ 3x+\frac{1}{2}=-\frac{5}{3}\end{matrix}\right.\Rightarrow \left[\begin{matrix} x=\frac{7}{18}\\ x=\frac{-13}{18}\end{matrix}\right.\)

d)

\(3^{2x+1}=81=3^4\)

\(\Rightarrow 2x+1=4\Rightarrow x=\frac{3}{2}\)

Khách vãng lai đã xóa
Akai Haruma
1 tháng 1 2020 lúc 9:12

Bài 1:

a)

\((\frac{3}{5})^2-[\frac{1}{3}:3-\sqrt{16}.(\frac{1}{2})^2]-(10.12-2014)^0\)

\(=\frac{9}{25}-(\frac{1}{9}-1)-1\)

\(=\frac{9}{25}-\frac{1}{9}=\frac{56}{225}\)

b)

\(|-\frac{100}{123}|:(\frac{3}{4}+\frac{7}{12})+\frac{23}{123}:(\frac{9}{5}-\frac{7}{15})\)

\(=\frac{100}{123}:\frac{4}{3}+\frac{23}{123}:\frac{4}{3}=(\frac{100}{123}+\frac{23}{123}):\frac{4}{3}=1:\frac{4}{3}=\frac{3}{4}\)

c)

\(\frac{(-5)^{32}.20^{43}}{(-8)^{29}.125^{25}}=\frac{5^{32}.(2^2.5)^{43}}{(-2)^{3.29}.(5^3)^{25}}=\frac{5^{32}.2^{86}.5^{43}}{-2^{87}.5^{75}}\)

\(=\frac{5^{32+43}.2^{86}}{-2^{87}.5^{75}}=\frac{5^{75}.2^{86}}{-2^{87}.5^{75}}=-\frac{1}{2}\)

Khách vãng lai đã xóa
Akai Haruma
1 tháng 1 2020 lúc 9:17

Bài 2:

a)

\(\frac{2}{3}-(\frac{3}{4}-x)=\sqrt{\frac{1}{9}}=\frac{1}{3}\)

\(\frac{3}{4}-x=\frac{2}{3}-\frac{1}{3}=\frac{1}{3}\)

\(x=\frac{3}{4}-\frac{1}{3}=\frac{5}{12}\)

b)

\((\frac{1}{2}-x)^2=(-2)^2=2^2\)

\(\Rightarrow \left[\begin{matrix} \frac{1}{2}-x=-2\\ \frac{1}{2}-x=2\end{matrix}\right.\Rightarrow \left[\begin{matrix} x=\frac{5}{2}\\ x=\frac{-3}{2}\end{matrix}\right.\)

c)

\(|3x+\frac{1}{2}|-\frac{2}{3}=1\)

\(|3x+\frac{1}{2}|=\frac{2}{3}+1=\frac{5}{3}\)

\(\Rightarrow \left[\begin{matrix} 3x+\frac{1}{2}=\frac{5}{3}\\ 3x+\frac{1}{2}=-\frac{5}{3}\end{matrix}\right.\Rightarrow \left[\begin{matrix} x=\frac{7}{18}\\ x=\frac{-13}{18}\end{matrix}\right.\)

d)

\(3^{2x+1}=81=3^4\)

\(\Rightarrow 2x+1=4\Rightarrow x=\frac{3}{2}\)

Khách vãng lai đã xóa
Nguyen Ngoc Lien
Xem chi tiết
Đứa Con Của Băng
14 tháng 10 2016 lúc 12:42

e)

=> (x-2) . (x+7) = ( x-1 ) . ( x +4)

=> x2 +7x - 2x -14 = x2 - x + 4x - 4

x2 + 5x - 14 = x2 + 3x - 4

=> 5x - 14  = 3x - 4

=> 5x  - 3x = 14-4

=> 2x         = 10 => x = 10 : 2 => x = 5

c)

=>( x-1) . 7 = ( x + 5 ) . 6

=> 7x - 7 = 6x + 30

=> 7x - 6x=  30 + 7

=> x         = 37

Vũ Đức Toàn
13 tháng 10 2016 lúc 21:03

a,x=\(\frac{5}{2}\)

b,x=\(\frac{13}{176}\)

c,x=37

d, x=\(\frac{12}{5}\)

e, x=5

Trà Mi Liên
Xem chi tiết
Nguyễn Như Ý
17 tháng 12 2015 lúc 18:34

a) \(=10\frac{1}{4}\cdot\frac{-5}{3}-8\frac{1}{4}\cdot\frac{-5}{3}-5=\left(10\frac{1}{4}-8\frac{1}{4}\right)\cdot\frac{-5}{3}-5\)

\(=\left(\frac{41}{4}-\frac{33}{4}\right)\cdot\frac{-5}{3}-5=2\cdot\frac{-5}{3}-5\)\(=\frac{-10}{3}-\frac{15}{3}=\frac{-25}{3}\)

b)\(=\frac{5}{7}+1+\frac{2}{7}+\frac{2^{10}\cdot\left(2^3\right)^3}{\left(2^2\right)^9}\)

\(=\frac{5}{7}+\frac{2}{7}+1+\frac{2^{10}\cdot2^9}{2^{27}}\)

\(=1+1+\frac{1}{2^8}=2+\frac{1}{256}=\frac{512}{256}+\frac{1}{256}=\frac{513}{256}\)