Tính nhanh:a)A=(\(19\frac{5}{8}\): \(\frac{7}{12}\)-13\(\frac{1}{4}\):\(\frac{7}{2}\))x\(\frac{4}{5}\)b)B=(\(9\frac{30303}{80808} 7\frac{303030}{808080}\)) 4.03Tìm x:\(5\frac{18}{17}:x \left(-\frac{4}...

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KL

Khánh Linh

3 tháng 6 2015

tính hợp lí

a)\(F=\left(9,75.21\frac{3}{7}+\frac{39}{4}.18\frac{4}{7}\right).\frac{15}{78}\)

b)\(H=\left(9\frac{30303}{80808}+7\frac{303030}{484848}\right)+4,03\)

1

DV

Đỗ Văn Hoài Tuân

3 tháng 6 2015

\(F=\left(9,75.21\frac{3}{7}+\frac{39}{4}.18\frac{4}{7}\right).\frac{15}{78}=\left(\frac{39}{4}.21\frac{3}{7}+\frac{39}{4}.18\frac{4}{7}\right).\frac{15}{78}=\left(\frac{39}{4}\left(21\frac{3}{7}+18\frac{4}{7}\right)\right).\frac{15}{78}=\left(\frac{39}{4}.40\right).\frac{15}{78}=390.\frac{15}{78}=75\)\(H=\left(9\frac{30303}{80808}+7\frac{303030}{484848}\right)+4,03=\left(9\frac{3}{8}+7\frac{30}{48}\right)+4,03=17+4,03=21,03\)

NC

Nguyễn Châu Mỹ Linh

24 tháng 6 2018

Tính giá trị biểu...

#Toán lớp 7

1

HA

Hoàng Anh Tuấn

4 tháng 10 2021

yutyugubhujyikiu

Đúng(1)

TD

Tứ diệp thảo mãi mãi yêu TFBOYS

27 tháng 1 2018

Bài 1: tính...

0

DD

Đỗ Diệu Linh

9 tháng 2 2017

Rút gọn

1. \(\frac{5}{9}.\frac{7}{13}+\frac{5}{9}.\frac{9}{13}-\frac{5}{9}.\frac{3}{13}\)

2. \(\left(\frac{1+\frac{1}{5}+\frac{1}{7}+\frac{1}{11}}{2+\frac{2}{5}+\frac{2}{7}+\frac{2}{17}}:\frac{4-\frac{4}{7}+\frac{4}{9}-\frac{4}{13}}{1-\frac{1}{7}+\frac{1}{9}-\frac{1}{13}}\right):\frac{838383}{808080}\)

1

T

thanhthanh5026

9 tháng 2 2017

1. \(\frac{5}{9}.\frac{7}{13}+\frac{5}{9}.\frac{9}{13}-\frac{5}{9}.\frac{3}{13}\)

= \(\frac{5}{9}\) .(\(\frac{7}{13}+\frac{9}{13}-\frac{3}{13}\) )

= \(\frac{5}{9}\) . 1 = \(\frac{5}{9}\)

MH

minh hoang cong

9 tháng 8 2019

Bai 1: a) \(\frac{3}{7}.\frac{-5}{9}+\frac{4}{9}.\frac{3}{7}-\frac{3}{7}.\frac{8}{9}\)
b) \(1\frac{13}{15}.0,75-\left(\frac{11}{20}+25\%\right):\frac{7}{5}\)
bài 2:
a) \(\frac{-3}{4}x-\frac{4}{10}=\frac{1}{5}\)
b) \(3\left(x-\frac{1}{3}\right)+\frac{1}{3}x=\frac{1}{19}:\frac{12}{19}\)
c)

2

NT

nguyen thi hien

9 tháng 8 2019

\(bai1:a,\frac{3}{7}\cdot\frac{-5}{9}+\frac{4}{9}\cdot\frac{3}{7}-\frac{3}{7}\cdot\frac{8}{9}\)

\(< =>\frac{-15}{63}+\frac{12}{63}-\frac{24}{63}\)

\(< =>\frac{-15+12-24}{63}\)

\(< =>\frac{-3}{7}\)

\(b,1\frac{13}{15}\cdot0,75-\left(\frac{11}{20}+25\%\right):\frac{7}{5}\)

\(< =>\frac{28}{15}\cdot\frac{3}{4}-\left(\frac{11}{20}+\frac{1}{4}\right):\frac{7}{5}\)

\(< =>\frac{7}{5}-\frac{4}{5}:\frac{7}{5}\)

\(< =>\frac{7}{5}-\frac{4}{7}\)

\(< =>\frac{29}{35}\)

\(bai2:\)

\(a,\frac{-3}{4}\cdot x-\frac{4}{10}=\frac{1}{5}\)

\(< =>\frac{-3}{4}\cdot x=\frac{1}{5}+\frac{4}{10}\)

\(< =>\frac{-3}{4}\cdot x=\frac{3}{5}\)

\(< =>x=\frac{3}{5}:\frac{-3}{4}\)

\(< =>x=\frac{-4}{5}\)

\(b,3\left(x-\frac{1}{3}\right)+\frac{1}{3}x=\frac{1}{19}:\frac{12}{19}\)

\(< =>3\left(x-\frac{1}{3}\right)+\frac{1}{3}x=\frac{1}{12}\)

\(< =>\left[3\left(x-\frac{1}{3}\right)\right]=\frac{1}{12}< =>x-\frac{1}{3}=\frac{1}{12}:3=\frac{1}{36}=>x=\frac{1}{36}+\frac{1}{3}=>x=\frac{13}{36}\)

\(< =>\left[\frac{1}{3}\cdot x\right]=\frac{1}{12}< =>x=\frac{1}{12}:\frac{1}{3}=>x=\frac{1}{4}\)

MM

minh man

9 tháng 8 2019

Bài 1:

a)\(\frac{3}{7}.\frac{-5}{9}+\frac{4}{9}.\frac{3}{7}-\frac{3}{7}.\frac{8}{9}\) b,\(1\frac{13}{15}.0,75-\left(\frac{11}{20}+25\%\right):\frac{7}{5}\)

\(=\frac{3}{7}.(\frac{-5}{9}+\frac{4}{9}-\frac{8}{9})\) \(=\frac{28}{15}.\frac{3}{4}-\left(\frac{11}{20}+\frac{5}{20}\right):\frac{7}{5}\)

\(=\frac{3}{7}.\frac{-9}{9}\) \(=\frac{7}{5}-\frac{4}{5}:\frac{7}{5}\)

\(=\frac{-3}{7}\) \(=\frac{7}{5}-\frac{4}{7}\)

\(=\frac{29}{35}\)

Bài 2:

a)\(\frac{-3}{4}x-\frac{4}{10}=\frac{1}{5}\) b,\(3\left(x-\frac{1}{3}\right)+\frac{1}{3}x=\frac{1}{19}:\frac{12}{19}\)

\(\frac{-3}{4}x\) \(=\frac{1}{5}+\frac{4}{10}\) \(3\left(x-\frac{1}{3}\right)+\frac{1}{3}x=\frac{1}{12}\)

\(\frac{-3}{4}x\) \(=\frac{3}{5}\) \(\left(x.3-\frac{1}{3}.3\right)+\frac{1}{3}x=\frac{1}{12}\)

\(x\) \(=\frac{3}{5}:\frac{-3}{4}\) \(\left(x.3-1\right)+\frac{1}{3}x=\frac{1}{12}\)

\(x\) \(=\frac{4}{-5}\) \(x.\left(3+\frac{1}{3}\right)-1=\frac{1}{12}\)

\(x.\left(3+\frac{1}{3}\right)=\frac{1}{12}+1\)

\(x.\frac{10}{3}=\frac{13}{12}\)

\(x=\frac{13}{12}:\frac{10}{3}\)

\(x=\frac{13}{40}\)

BÀI ÔN SỐ HỌC1. Thực hiện mỗi phép tính sau bằng 2 cách:a)\(3\frac{4}{9}+5\frac{1}{6}\)Ví dụ :Cách 1: \(3\frac{4}{9}+5\frac{1}{6}=\frac{31}{9}+\frac{31}{6}=\frac{62}{18}+\frac{93}{18}=\frac{155}{18}=8\frac{11}{18}\)Cách 2:\(3\frac{4}{9}+5\frac{1}{6}=3\frac{8}{18}+5\frac{3}{18}=8\frac{11}{18}\)b)\(8\frac{1}{14}-6\frac{3}{7}\)c)\(7-3\frac{6}{7}\)2. Áp dụng tính chất phép tính & qui tắc dấu ngoặc để tính giá trị các biểu thức sau:a)A...

LT

Lê Thị Phương Nhi

21 tháng 4 2017

0

HQ

Hoàng Quân

20 tháng 3 2016

Tìm x:

\(\frac{\left(13\frac{2}{9}-15\frac{2}{3}\right)\cdot\left(30^2-5^4\right)}{\left(18\frac{3}{7}-17\frac{1}{4}\right)\cdot\left(25-12\cdot5^2\right)}\cdot x=\frac{\frac{2}{11}+\frac{3}{13}+\frac{4}{15}+\frac{5}{17}}{4\frac{1}{11}+\frac{5}{13}+\frac{9}{15}+\frac{13}{17}}\)