tìm x : a) \(\dfrac{x 1}{7} \dfrac{x 1}{8}=\dfrac{x 1}{9} \dfrac{x 1}{10}\) b) \(\dfrac{x 1}{12} \dfrac{x^2}{11}=\dfrac{x 3}{10} \dfrac{x 4}{9}\) c) \(\dfrac{x-2}{x-1}=\dfrac{x 4}{x 7}\) d)\(\dfra...

#Toán lớp 7

1

N

nguyenthanhtra

24 tháng 7 2017

mn ơi giúp nhé

tìm x , biết:a) \(x\) : \(4\dfrac{1}{3}\) = -2,5 b) \(\dfrac{3}{5}x\) + \(\dfrac{1}{4}\) = \(\dfrac{1}{10}\)c) \(2\dfrac{7}{9}\) \(-\) \(\dfrac{12}{13}x\) = \(\dfrac{7}{9}\) ...

QA

Quỳnh Anh Daisy

24 tháng 7 2021

1

VV

Vân Vui Vẻ

24 tháng 7 2021

a, \(x\) : \(\dfrac{13}{3}\) = -2,5

\(x\) = -2,5 . \(\dfrac{13}{3}\)

\(x\) = \(\dfrac{65}{6}\)

b,\(\dfrac{3}{5}\)\(x\) = \(\dfrac{1}{10}-\)\(\dfrac{1}{4}\)

\(\dfrac{3}{5}x\) = \(\dfrac{-3}{20}\)

\(x\) = \(\dfrac{-3}{20}\) : \(\dfrac{3}{5}\)

\(x\) = \(\dfrac{-1}{4}\)

c, \(\dfrac{25}{9}-\dfrac{12}{13}x=\dfrac{7}{9}\)

\(\dfrac{12}{13}x\)\(=\dfrac{25}{9}-\dfrac{7}{9}\)

\(\dfrac{12}{13}x=2\)

\(x=2:\dfrac{12}{13}\)

\(x=\dfrac{13}{6}\)

tìm x :a, x . \(\dfrac{-5}{8}\) = \(\dfrac{15}{32}\) b, \(\dfrac{3}{10}\) : x =\(\dfrac{-9}{20}\)c, \(\dfrac{-1}{4}\) x + \(\dfrac{4}{5}\) =\(\dfrac{3}{4}\) d, \(\dfrac{-7}{8}\) + \(\dfrac{2}{3}\) :x...

MN

Minh Ngọc 5D - Tuệ Minh1G

25 tháng 3 2023

a) x + \(\dfrac{2}{5}\) = \(\dfrac{1}{2}\)b) x - \(\dfrac{2}{5}\) = \(\dfrac{2}{7}\)c) \(\dfrac{3}{5}\) - x = \(\dfrac{1}{10}\)d) x . \(\dfrac{3}{4}\) = \(\dfrac{9}{20}\)e) x : \(\dfrac{1}{7}\) = 14f) ( \(\dfrac{1}{4}\) + x ) . \(\dfrac{1}{2}\) = \(\dfrac{2}{5}\)g) x . \(\dfrac{2}{3}\) - \(\dfrac{2}{3}\) = \(\dfrac{9}{12}\)h) \(\dfrac{3}{4}\) + \(\dfrac{1}{4}\) : x = \(\dfrac{2}{5}\)k) \(3\dfrac{4}{5}\) - x = \(\dfrac{18}{5}\)l) x . \(2\dfrac{1}{3}\) = \(\dfrac{3}{4}\)m) x...

4

NK

Ng KimAnhh

25 tháng 3 2023

a, \(x\cdot\dfrac{-5}{8}=\dfrac{15}{32}\)

\(x=\dfrac{15}{32}:\dfrac{-5}{8}\)

\(x=\dfrac{-3}{4}\)

b, \(\dfrac{3}{10}:x=\dfrac{-9}{20}\)

\(x=\dfrac{3}{10}:\dfrac{-9}{20}\)

\(x=-\dfrac{2}{3}\)

c, \(\dfrac{-1}{4}x+\dfrac{4}{5}=\dfrac{3}{4}\)

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

\(\dfrac{-1}{4}x=-\dfrac{1}{20}\)

\(x=-\dfrac{1}{20}:\dfrac{-1}{4}\)

\(x=\dfrac{1}{5}\)

d, \(\dfrac{-7}{8}+\dfrac{2}{3}:x=\dfrac{3}{5}\cdot\dfrac{-5}{12}\)

\(\dfrac{-7}{8}+\dfrac{2}{3}:x=-\dfrac{1}{4}\)

\(\dfrac{2}{3}:x=-\dfrac{1}{4}+\dfrac{-7}{8}\)

\(\dfrac{2}{3}:x=\dfrac{5}{8}\)

\(x=\dfrac{2}{3}:\dfrac{5}{8}\)

\(x=\dfrac{16}{15}\)

#YVA6

Đúng(3)

TT

Thư Thư

25 tháng 3 2023

\(a,x.\dfrac{-5}{8}=\dfrac{15}{32}\)

\(\Leftrightarrow x=\dfrac{15}{32}:\dfrac{-5}{8}\)

\(\Leftrightarrow x=\dfrac{15}{32}.\dfrac{-8}{5}\)

\(\Leftrightarrow x=-\dfrac{3}{4}\)

\(b,\dfrac{3}{10}:x=-\dfrac{9}{20}\)

\(\Leftrightarrow x=\dfrac{3}{10}:\dfrac{-9}{20}\)

\(\Leftrightarrow x=\dfrac{3}{10}.\dfrac{-20}{9}\)

\(\Leftrightarrow x=-\dfrac{2}{3}\)

\(c,-\dfrac{1}{4}x+\dfrac{4}{5}=\dfrac{3}{4}\)

\(\Leftrightarrow-\dfrac{1}{4}x=\dfrac{3}{4}-\dfrac{4}{5}\)

\(\Leftrightarrow-\dfrac{1}{4}x=-\dfrac{1}{20}\)

\(\Leftrightarrow x=-\dfrac{1}{20}\times\left(-4\right)\)

\(\Leftrightarrow x=\dfrac{1}{5}\)

\(d,-\dfrac{7}{8}+\dfrac{2}{3}:x=\dfrac{3}{5}.\dfrac{-5}{12}\)

\(\Leftrightarrow-\dfrac{7}{8}+\dfrac{2}{3}:x=-\dfrac{1}{4}\)

\(\Leftrightarrow\dfrac{2}{3}:x=-\dfrac{1}{4}+\dfrac{7}{8}\)

\(\Leftrightarrow\dfrac{2}{3}:x=\dfrac{5}{8}\)

\(\Leftrightarrow x=\dfrac{2}{3}:\dfrac{5}{8}\)

\(\Leftrightarrow x=\dfrac{16}{15}\)

Đúng(2)

G

??gsg

14 tháng 8 2023

1

NL

Nguyễn Lê Phước Thịnh

14 tháng 8 2023

a: x+2/5=1/2

=>x=1/2-2/5=5/10-4/10=1/10

b; x-2/5=2/7

=>x=2/7+2/5=10/35+14/35=24/35

c: 3/5-x=1/10

=>x=3/5-1/10=6/10-1/10=5/10=1/2

d: x*3/4=9/20

=>x=9/20:3/4=9/20*4/3=36/60=3/5

e: x:1/7=14

=>x=14*1/7=2

f: =>x+1/4=2/5:1/2=4/5

=>x=4/5-1/4=16/20-5/20=11/20

g: =>x*2/3=9/12+2/3=3/4+2/3=9/12+8/12=17/12

=>x=17/12:2/3=17/12*3/2=51/24=17/8

VA

Vân Anh Nguyễn

24 tháng 6 2021

a,\(\dfrac{1}{7}\text{x}\dfrac{2}{7}+\dfrac{1}{7}\text{x}\dfrac{5}{7}+\dfrac{6}{7}\) b,\(\dfrac{6}{11}\text{x}\dfrac{4}{9}+\dfrac{6}{11}\text{x}\dfrac{7}{9}-\dfrac{6}{11}\text{x}\dfrac{2}{9}\)

c, \(\dfrac{4}{25}\text{x}\dfrac{5}{8}\text{x}\dfrac{25}{4}\text{x}24\)

#Toán lớp 5

3

Y

Yeutoanhoc

24 tháng 6 2021

`a)1/7xx2/7+1/7xx5/7+6/7`

`=1/7xx(2/7+5/7)+6/7`

`=1/7xx1+6/7`

`=1/7+6/7=1`

`b)6/11xx4/9+6/11xx7/9-6/11xx2/9`

`=6/11xx(4/9+7/9-2/9)`

`=6/11xx9/9`

`=6/11`

Đúng(3)

Y

Yeutoanhoc

24 tháng 6 2021

Sorry nãy ghi thiếu.

`c)4/25xx5/8xx25/4xx24`

`=(4xx5xx25xx24)/(25xx8xx4)`

`=(4xx5xx24)/(4xx8)`

`=(5xx24)/8`

`=5xx3=15`

Đúng(3)

NN

Nguyễn ngọc Khế Xanh

3 tháng 4 2021

Tìm x biết

a) \(\dfrac{x}{3}=\dfrac{7}{25}+\dfrac{-1}{5}\)

b)\(\dfrac{4}{9}+\dfrac{x}{5}=\dfrac{5}{11}\)

c) \(\dfrac{-5}{9}+\dfrac{x}{10}=\dfrac{1}{3}\)

3

NL

Nguyễn Lê Phước Thịnh

3 tháng 4 2021

a) Ta có: \(\dfrac{x}{3}=\dfrac{7}{25}+\dfrac{-1}{5}\)

\(\Leftrightarrow\dfrac{x}{3}=\dfrac{7}{25}+\dfrac{-5}{25}=\dfrac{2}{25}\)

hay \(x=\dfrac{6}{25}\)

Vậy: \(x=\dfrac{6}{25}\)

NL

Nguyễn Lê Phước Thịnh

3 tháng 4 2021

b) Ta có: \(\dfrac{4}{9}+\dfrac{x}{5}=\dfrac{5}{11}\)

\(\Leftrightarrow\dfrac{x}{5}=\dfrac{5}{11}-\dfrac{4}{9}=\dfrac{45}{99}-\dfrac{44}{99}=\dfrac{1}{99}\)

hay \(x=\dfrac{5}{99}\)

Vậy: \(x=\dfrac{5}{99}\)

CD

Chócứsủa Đoànngườicứđi Sốngchođángđ...

19 tháng 1 2018

giải phương trình sau:

a) \(\dfrac{8}{x-8}+\dfrac{11}{x-11}=\dfrac{9}{x-9}+\dfrac{10}{x-10}\)

b) \(\dfrac{x}{x-3}-\dfrac{x}{x-5}=\dfrac{x}{x-4}-\dfrac{x}{x-6}\)

c) \(\dfrac{4}{x^2-3x+2}-\dfrac{3}{2x^2-6x+1}+1=0\)

d) \(\dfrac{1}{x-1}+\dfrac{2}{x-2}+\dfrac{3}{x-3}=\dfrac{6}{x-6}\)

#Toán lớp 8

1

TA

TNA Atula

19 tháng 1 2018

a/\(\dfrac{8}{x-8}+1+\dfrac{11}{x-11}+1=\dfrac{9}{x-9}+1+\dfrac{10}{x-10}+1\)

=>\(\dfrac{8+x-8}{x-8}+\dfrac{11+x-11}{x-11}=\dfrac{9+x-9}{x-9}+\dfrac{10+x-10}{x-10}\)

=>\(\dfrac{x}{x-8}+\dfrac{x}{x-11}-\dfrac{x}{x-9}-\dfrac{x}{x-10}=0\)

=>x.\(\left(\dfrac{1}{x-8}+\dfrac{1}{x-11}+\dfrac{1}{x-9}+\dfrac{1}{x-10}\right)=0\)

=>x=0

b/\(\dfrac{x}{x-3}-1+\dfrac{x}{x-5}-1=\dfrac{x}{x-4}-1+\dfrac{x}{x-6}-1\)

=>\(\dfrac{x-x+3}{x-3}+\dfrac{x-x+5}{x-5}-\dfrac{x-x+4}{x-4}-\dfrac{x-6+6}{x-6}=0\)

=>\(\dfrac{3}{x-3}+\dfrac{5}{x-5}-\dfrac{4}{x-4}-\dfrac{6}{x-6}=0\)

Đến đây thì bạn giải giống câu a

CD

Chócứsủa Đoànngườicứđi Sốngchođángđ...

19 tháng 1 2018

giải cho mk 2 câu cuối đi

a.\(\dfrac{4x-5}{x-1}=2+\dfrac{x}{x-1}\) b.\(\dfrac{7}{x+2}=\dfrac{3}{x-5}\) c.\(\dfrac{2x+5}{2x}-\dfrac{x}{x+5}=0\)d.\(\dfrac{12x+1}{11x-4}+\dfrac{10x-4}{9}=\dfrac{20x+17}{18}\) e.\(\dfrac{11}{x}=\dfrac{9}{x+1}+\dfrac{2}{x-4}\) ...

NH

NGo HOANG 2

11 tháng 3 2023

#Toán lớp 8

2

NH

Ngô Hải Nam

11 tháng 3 2023

bạn tách một câu vài câu hỏi chứ đừng gộp như thế này ko ai trả lời đâu

NL

Nguyễn Lê Phước Thịnh

11 tháng 3 2023

a: =>\(4x-5=2x-2+x=3x-2\)

=>x=3

b: \(\Leftrightarrow7x-35=3x+6\)

=>4x=41

=>x=41/4

c: =>(2x+5)(x+5)-2x^2=0

=>2x^2+10x+5x+25-2x^2=0

=>15x=-25

=>x=-5/3

e: \(\Leftrightarrow\dfrac{11}{x}=\dfrac{9x-36+2x+2}{\left(x+1\right)\left(x-4\right)}\)

=>11(x^2-3x-4)=x(11x-34)

=>11x^2-33x-44=11x^2-34x

=>x=44

Tìm \(x\) biết:\(a.x=\dfrac{1}{5}+\dfrac{-3}{7}\) \(b.\dfrac{3}{5}-\dfrac{4}{7}\div x=\dfrac{-9}{10}\) \(c.x-\left(\dfrac{-3}{4}\right)=\dfrac{-2}{3}-\dfrac{1}{2}\) ...

CH

Chử Hải Yến

3 tháng 4 2022

Tìm x, biết: a) \(\dfrac{1}{20}\) - (x - \(\dfrac{8}{5}\)) = \(\dfrac{1}{10}\) b) \(\dfrac{7}{4}\) - (x + \(\dfrac{5}{3}\)) = \(\dfrac{-12}{5}\) c) x - [\(\dfrac{17}{2}\) - \(\left(\dfrac{-3}{7}+\dfrac{5}{3}\right)\)]...

1

TT

Thư Thư

3 tháng 4 2022

\(a,x=\dfrac{1}{5}+\dfrac{-3}{7}\)

\(x=\dfrac{7}{35}+\dfrac{-15}{35}\)

\(x=-\dfrac{8}{35}\)

\(b,\dfrac{3}{5}-\dfrac{4}{7}:x=\dfrac{-9}{10}\)

\(\dfrac{4}{7}:x=\dfrac{3}{5}-\dfrac{-9}{10}\)

\(\dfrac{4}{7}:x=\dfrac{3}{2}\)

\(x=\dfrac{4}{7}:\dfrac{3}{2}\)

\(x=\dfrac{4}{7}\times\dfrac{2}{3}\)

\(x=\dfrac{8}{21}\)

\(c,x-\left(\dfrac{-3}{4}\right)=\dfrac{-2}{3}-\dfrac{1}{2}\)

\(x+\dfrac{3}{4}=\dfrac{-4}{6}-\dfrac{3}{6}\)

\(x+\dfrac{3}{4}=-\dfrac{7}{6}\)

\(x=-\dfrac{7}{6}-\dfrac{3}{4}\)

\(x=-\dfrac{23}{12}\)

\(d,\dfrac{-5}{9}-x=\dfrac{1}{3}+\dfrac{7}{18}\)

\(\dfrac{-5}{9}-x=\dfrac{6}{18}+\dfrac{7}{18}\)

\(\dfrac{-5}{9}-x=\dfrac{13}{18}\)

\(x=\dfrac{-5}{9}-\dfrac{13}{18}\)

\(x=\dfrac{-10}{18}-\dfrac{13}{18}\)

\(x=-\dfrac{23}{18}\)

Đúng(2)

LP

Lê Phương Linh

1 tháng 11 2023

#Toán lớp 7

2

NT

Nguyễn Thùy Dương

1 tháng 11 2023