Bài 1 : Tính hợp lí a) \(\frac{7}{-25} \frac{-18}{25} \frac{4}{23} \frac{5}{7} \frac{19}{23}\) b) \(\frac{7}{19}.\frac{8}{11} \frac{7}{19}.\frac{3}{11} \frac{12}{19}\) c) \(8\frac{2}{7}-\l...

0

ST

Song Trần

23 tháng 7 2016

Tính giá trị biểu thức:

3) C= \(\frac{5}{18}+\frac{8}{19}-\frac{7}{21}+\left(\frac{-10}{36}+\frac{11}{19}+\frac{1}{3}\right)-\frac{5}{8}\)\(\frac{5}{8}\)

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

#Toán lớp 7

3

NV

nguyễn văn nghĩa

23 tháng 7 2016

c=39/64

d=913/105

SK

Sherlockichi Kudoyle

23 tháng 7 2016

3) C thiếu đề

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

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

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

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

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

Giải giùm mk zới mn~~~~tặng người đầu tiên làm 4 tick nha(đảm bảo lên 4 điểm...

HI

Ƭhiêท ᗪii

9 tháng 2 2019

1

CT

Cố Tử Thần

9 tháng 2 2019

â, -4/9(7/15+8/15)=-4/9

b,-5/4(16/25+9/25)=-5/4

,.....

dài quá mik làm ko hết

hok tốt

CY

Choi Yuna

27 tháng 6 2018

...

Bài 4: THực hiện phép tính một cách hợp lý:a) \(\frac{7}{19}.\frac{8}{11}+\frac{3}{11}.\frac{7}{19}+\frac{-12}{19}\) b) \(\frac{-7}{25}.\frac{39}{-14}.\frac{50}{78}\) ...

0

TQ

Trần Quang Hiếu

25 tháng 7 2016

3

VD

Võ Đông Anh Tuấn

25 tháng 7 2016

a ) \(\frac{7}{19}.\frac{8}{11}+\frac{3}{11}.\frac{7}{19}+\frac{-12}{19}\)

\(=\frac{7}{19}.\left(\frac{8}{11}+\frac{3}{11}\right)+\frac{-12}{19}\)

\(=\frac{7}{19}.\frac{11}{11}+\frac{-12}{19}\)

\(=\frac{7}{19}.1+\frac{-12}{19}\)

\(=\frac{7}{19}+\frac{-12}{19}\)

\(=\frac{7+\left(-12\right)}{19}\)

\(=-\frac{5}{19}\)

b ) \(\frac{-7}{25}.\frac{39}{-14}.\frac{50}{78}=\frac{-7.39.50}{25.-14.78}=\frac{-1.1.2}{1.-2.2}=\frac{-2}{-4}=\frac{1}{2}\)

c ) \(\left(\frac{3}{8}+\frac{-3}{4}+\frac{7}{12}\right):\frac{5}{6}+\frac{1}{2}\)

\(=\frac{5}{24}:\frac{5}{6}+\frac{1}{2}\)

\(=\frac{5}{24}.\frac{6}{5}+\frac{1}{2}\)

\(=\frac{1}{4}+\frac{1}{2}\)

\(=\frac{3}{4}\)

NN

Nobi Nobita

25 tháng 7 2016

a)\(\frac{7}{19}.\frac{8}{11}+\frac{3}{11}.\frac{7}{19}+\frac{-12}{19}=\frac{7}{19}.\frac{8}{11}+\frac{3}{11}.\frac{7}{19}+\frac{7}{19}.\frac{-12}{7}=\frac{7}{19}.\left(\frac{8}{11}+\frac{3}{11}+-\frac{12}{7}\right)=\frac{7}{19}.\left(\frac{-5}{7}\right)=-\frac{5}{19}\)

b)\(\frac{-7}{25}.\frac{39}{-14}.\frac{50}{78}=\frac{\left(-7\right).39.50}{25.\left(-14\right).78}=\frac{\left(-7\right).3.13.2.5.5}{5.5.\left(-7\right).2.2.13.3}=\frac{1}{2}\)

c)\(\left(\frac{3}{8}+\frac{-3}{4}+\frac{7}{12}\right):\frac{5}{6}+\frac{1}{2}=\frac{5}{24}:\frac{5}{6}+\frac{1}{2}=\frac{2}{7}+\frac{1}{2}=\frac{11}{14}\)

NC

Nguyễn Châu Mỹ Linh

24 tháng 6 2018

Tính giá trị biểu...

1) tính nhanh.a)\(\frac{-2}{17}+\frac{15}{23}+\frac{\left(-15\right)}{17}+\frac{4}{19}+\frac{8}{23}\)b)\(\frac{7}{19}.\frac{8}{11}+\frac{7}{19}.\frac{3}{11}+\frac{12}{19}\)2 tínha)\(\frac{1}{3}+\frac{\left(-2\right)}{16}-\frac{7}{14}\) b) \(11\frac{3}{13}-\hept{ }2\frac{4}{7}+5\frac{3}{13}\) c) \(0,7.2\frac{2}{3}.20.,0375.\frac{5}{28}\) d)\(\frac{6}{7}+\frac{5}{7}:5-\frac{8}{9}\) Mình đang cần gấp lắm hãy giúp...

#Toán lớp 7

1

HA

Hoàng Anh Tuấn

4 tháng 10 2021

yutyugubhujyikiu

Đúng(1)

NT

nguyễn trúc linh

1 tháng 4 2019

2

S

_Shadow_

1 tháng 4 2019

1. a) \(\frac{-2}{7}+\frac{15}{23}+\frac{\left(-15\right)}{17}+\frac{4}{19}+\frac{8}{23}\)

\(=\left(\frac{-2}{7}+\frac{-5}{7}\right)+\left(\frac{15}{23}+\frac{8}{23}\right)+\frac{4}{19}\)

\(=\left(-1\right)+1+\frac{4}{19}\)

\(=0+\frac{4}{19}=\frac{4}{19}\)

b) \(\frac{7}{19}\cdot\frac{8}{11}+\frac{7}{19}\cdot\frac{3}{11}+\frac{12}{19}\)

\(=\frac{7}{19}\cdot\left(\frac{8}{11}+\frac{3}{11}\right)+\frac{12}{19}\)

\(=\frac{7}{19}\cdot1+\frac{12}{19}\)

\(=\frac{7}{19}+\frac{12}{19}=\frac{19}{19}=1\)

S

_Shadow_

1 tháng 4 2019

2. a) \(\frac{1}{3}+\frac{\left(-2\right)}{16}-\frac{7}{14}\)

\(=\frac{5}{24}-\frac{1}{2}\)

\(=-\frac{7}{24}\)

b) \(11\frac{3}{13}-2\frac{4}{7}+5\frac{3}{13}\)

\(=\left(11-2+5\right)+\frac{3}{13}-\frac{4}{7}+\frac{3}{13}\)

\(=14+\left(-\frac{10}{91}\right)\)

\(=-14\frac{10}{91}\)

c) \(0,7\cdot2\frac{2}{3}\cdot20\cdot0,375\cdot\frac{5}{28}\)

\(=\frac{7}{10}\cdot\frac{8}{3}\cdot20\cdot\frac{3}{8}\cdot\frac{5}{28}\)

\(=\left(\frac{7}{10}\cdot\frac{5}{28}\right)\cdot\left(\frac{8}{3}\cdot\frac{3}{8}\right)\cdot20\)

\(=\frac{1}{8}\cdot1\cdot20\)

\(=\frac{20}{8}=\frac{5}{2}\)

d) \(\frac{6}{7}+\frac{5}{7}:5-\frac{8}{9}\)

\(=\frac{6}{7}+\frac{1}{7}-\frac{8}{9}\)

\(=1-\frac{8}{9}\)

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

~Học tốt~

BÀI 1:a/ \(\frac{2}{7}+\frac{-3}{8}+\frac{11}{7}+\frac{1}{3}+\frac{1}{7}+\frac{5}{-8}\)b/ \(\frac{-3}{8}+\frac{12}{25}+\frac{5}{-8}+\frac{2}{-5}+\frac{13}{25}\)c/ \(\frac{7}{8}+\frac{1}{8}.\frac{3}{8}+\frac{1}{8}.\frac{5}{8}\)d/ \(\frac{-5}{6}.\frac{4}{19}+\frac{-7}{12}.\frac{4}{19}-\frac{40}{57}\)e/ \(\frac{3}{7}.\frac{9}{26}-\frac{1}{14}.\frac{1}{13}-\frac{1}{7}\)f/ \(\left(\frac{2}{3}-\frac{1}{...

HL

Hỏa Long

27 tháng 3 2018

3

TN

Thái Ngọc Minh Anh

9 tháng 4 2018

a) 2/7+-3/8+11/7+1/3+1/7+5/-8

=(2/7+11/7+1/7)+(3/8+-5/8)+1/3

=2+2+1/3

=4+1/3

=13/3

b) -3/8+12/25+5/-8+2/-5+13/25

=(-3/8+-5/8)+(12/25+13/25)+-2/5

=-1+1+-2/5

=0+-2/5

=-2/5

c)7/8+1/8*3/8+1/8*5/8

=7/8+1/8*(3/8+5/8)

=7/8+1/8*1

=7/8+1/8

=1

PV

phạm văn tuấn

9 tháng 4 2018

a) 2/7+-3/8+11/7+1/3+1/7+5/-8

=(2/7+11/7+1/7)+(3/8+-5/8)+1/3

=2+2+1/3

=4+1/3

=13/3

b) -3/8+12/25+5/-8+2/-5+13/25

=(-3/8+-5/8)+(12/25+13/25)+-2/5

=-1+1+-2/5

=0+-2/5

=-2/5

c)7/8+1/8*3/8+1/8*5/8

=7/8+1/8*(3/8+5/8)

=7/8+1/8*1

=7/8+1/8

=1

bài 1:thực hiện phép tính...

TD

Tứ diệp thảo mãi mãi yêu TFBOYS

21 tháng 1 2018

0

DD

Đỗ Diệu Linh

9 tháng 2 2017

Rút gọn

1.\(\frac{7}{19}.\frac{8}{11}+\frac{7}{19}.\frac{3}{11}+\frac{12}{19}\)

2.\(\frac{\frac{2}{5}+\frac{2}{7}-\frac{2}{9}-\frac{2}{11}}{\frac{4}{5}+\frac{4}{7}-\frac{4}{9}-\frac{4}{11}}\)

2

HT

Hoàng Thị Ngọc Anh

9 tháng 2 2017

\(1\)) \(\frac{7}{19}.\frac{8}{11}+\frac{7}{19}.\frac{3}{11}+\frac{12}{19}\)

\(=\frac{7}{19}\left(\frac{8}{11}+\frac{3}{11}\right)+\frac{12}{19}\)

\(=\frac{7}{19}+\frac{12}{19}\)

\(=1\)

\(2\)) \(\frac{\frac{2}{5}+\frac{2}{7}-\frac{2}{9}-\frac{2}{11}}{\frac{4}{5}+\frac{4}{7}-\frac{4}{9}-\frac{4}{11}}\)

\(=\frac{\frac{2}{5}+\frac{2}{7}-\frac{2}{9}-\frac{2}{11}}{2\left(\frac{2}{5}+\frac{2}{7}-\frac{2}{9}-\frac{2}{11}\right)}\)

\(=\frac{1}{2}\)

HT

Huy Thắng Nguyễn

9 tháng 2 2017

1. \(\frac{7}{19}\times\frac{8}{11}+\frac{7}{19}\times\frac{3}{11}+\frac{12}{19}\)

\(=\frac{7}{19}\left(\frac{8}{11}+\frac{3}{11}\right)+\frac{12}{19}\)

\(=\frac{7}{19}\times1+\frac{12}{19}=\frac{19}{19}=1\)

2. \(\frac{\frac{2}{5}+\frac{2}{7}-\frac{2}{9}-\frac{2}{11}}{\frac{4}{5}+\frac{4}{7}-\frac{4}{9}-\frac{4}{11}}\)

\(=\frac{\frac{2}{5}+\frac{2}{7}-\frac{2}{9}-\frac{2}{11}}{2\left(\frac{2}{5}+\frac{2}{7}-\frac{2}{9}-\frac{2}{11}\right)}=\frac{1}{2}\)