Tìm x, biết: a) ( 2,8x - 32 ) : 2/3 = - 90 b) ( 4,5 - 2x ) . 1 4/7 = 11/14c) ( x 1/4 - 1/3 ) : ( 2 1/6 - 1/4 ) = 7/46d) 13/15 - ( 13/21 x ) . 7/12 = 7/10e) 5/|x| - 4/3 = 38/24g) 7/9

CD

cuộc đời buồn bã

27 tháng 3 2019 - olm

Tìm x, biết: a) ( 2,8x - 32 ) : 2/3 = - 90 b) ( 4,5 - 2x ) . 1 4/7 = 11/14c) ( x + 1/4 - 1/3 ) : ( 2 + 1/6 - 1/4 ) = 7/46d) 13/15 - ( 13/21 + x ) . 7/12 = 7/10e) 5/|x| - 4/3 = 38/24g) 7/9 - |x|/3 = 1/9h) [ 4/9 + ( 3/8x - 1/2 ) : 5/7 ]. 6/11 = 18/55i) 2/9.(3x - 1/2) - 5/6 = -1 1/3k) 5x - 1 1/2x - 0,5x = -1 5/6m) 1/3.5 + 1/ 5.7 + 1/ 7.9 +.....+ 1/ x(x + 2) = 1/9 ( x thuộc N* )n) 1/21 + 1/28 + 1/36 +.....+ 2/ x(x+1) = 2/9 ( x thuộc N*...

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#Toán lớp 6

0

PP

Pi Pi

20 tháng 7 2018 - olm

Tìm x:

a) (2,8x - 32) :\(\frac{2}{3}\)=90

b) 4,5 - 2x . \(1\frac{4}{7}\)=\(\frac{11}{14}\)

c) (x+ \(\frac{1}{4}-\frac{1}{3}\) ): (2+\(\frac{1}{6}-\frac{1}{4}\))=\(\frac{7}{46}\)

d)\(\frac{13}{15}-\left(\frac{13}{21}+x\right).\frac{7}{12}=\frac{7}{10}\)

#Toán lớp 4

1

FN

๖ۣۜFunny-Ngốkツ

20 tháng 7 2018

\(\left(2.8x-32\right):\frac{2}{3}=90\)

\(2.8\cdot x-32=90\cdot\frac{2}{3}\)

\(\frac{14}{5}x-32=60\)

\(\frac{14}{5}x=60+32\)

\(\frac{14}{5}x=92\)

\(x=\frac{230}{7}\)

B , c , d tương tự

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NT

Nguyễn Trúc Phương

16 tháng 4 2016 - olm

Tìm x biet:

a,5/2x+x=32/15

b,x-7/2x=-32/15

c,-7/3x-7/4x+11/3=18/5

d,-5/6-3x=2/3

e,2x-5/9=-2/3

f,1/2-2/3x=7/12

g,7-|2x-3|=4

h,(19x+2.5^2):14=(13-8)^2-4^2

i,3/4x-2/3=2/7.1/6+5/7.1/6

k,(x+1/2).(2/3-2x)=0

l,x/2013-1/10-1/15-1/21-........-1/120=5/8

#Toán lớp 6

0

I

iamshayuri

28 tháng 1 2023

(đăng cho các CTV thử việc ^-^)

Tìm x:

a, -5/6 - x = 7/12 + -1/3

b, (4,5 - 2x).(-1 4/7) = 11/14

c, (2/11 + 1/3).x = (1/7 - 1/8).56

#Toán lớp 6

1

2

2611

28 tháng 1 2023

`a)-5/6-x=7/12+[-1]/3`

`-5/6-x=1/4`

`x=-5/6-1/4`

`x=-13/12`

`b)(4,5-2x).(-1 4/7)=11/14`

`(4,5-2x).(-11/7)=11/14`

`4,5-2x=11/14:(-11/7)=-0,5`

`2x=4,5-(-0,5)=5`

`x=5:2=2,5`

`c)(2/11+1/3)x=(1/7-1/8).56`

`17/33 x=1/56 .56=1`

`x=33/17`

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NH

nguyen hoang le thi

19 tháng 4 2016 - olm

Tìm x, biết:

a) (2,8x - 32) : 2/3 = -90

b) (4,5 - 2x) . 1 4/7(hỗn số) = 11/14

#Toán lớp 6

1

DT

Đỗ Thị Thu Hằng

19 tháng 4 2016

a) x=-10

b)x=2

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RC

ranh con tinh nghich

27 tháng 7 2017 - olm

Bài 1:1)-7/9x2 3/42)2/3+1/3x-2/53) 3/4 x 15 1/3 - 3/4 x 43 1/34) (-49,1)x 13/27 - 58,9 x 13/275) 0,375 : (-4,5)6) 3 1/7 :( -1 3/7)7) 9 1/3 :4 2/3 - 28) ( 7 3/4 : 0,3125 + 4,5 x2 2/45) : (-8,5)Bài 2 A= (-6/11) x 7/10 x (11/-6) x(-20)B= (-1/9) x (-17/29) x 58/51C=(-3/7) x 5/11 +(-5/14)x5/11D=(1 1/27 x 12/23 x 9/14 ) :(-3/23)Bài 3 tìm xa) 3/7x -2/5 x+-17/33b)(3/4 x - 9/16).(1/3 +-3/5 : x)=0c)(x+3/5 ) . (x+1)<0(Hạn thứ 3 nha , giúp mk...

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#Toán lớp 6

0

LB

Lam Bao Ngoc

7 tháng 3 2018 - olm

1,x/7 x 4/9 x 5 = 3x4x5/7x9

2, tích của 2 phân số tối giản có tử số khác 1 = 6/35 . Tìm tổng của 2 phân số ?

3, tính = cách thuận tiện nhất

a, 6/7 x 16/15 x 7/6 x 21/32 =.....................................

b, 21/17 x 13/14 x 56 x 3/42 =.................................

c, 7/4 x 11/21 + 11/21 x 5/4 =...........................

d, 23/14 x 6/13 - 9/14 x 6/13 =.............................

#Toán lớp 4

0

YN

Yến Nhi Sky M-tp

2 tháng 6 2017

a. 2/3x-1/2=1/10

b. 39/7:x=13

c. (14/5x-50):2/3=51

d. (x+1/2)(2/3-2x)=0

e. 2/3x-1/2x=5/12

g. (x.44/7+3/7)11/5-3/7=-2

h. x.13/4+(-7/6)x-5/3=5/12

i.93/17:x+(-4/17):x+22/7:52/3=4/11

j. 17/2-|2x-3/4|=-7/4

k. (x+1/5)^2+17/25=26/25

l. -32/27-(3x-7/9)^3=-24/27

#Toán lớp 6

1

BT

Băng Tâm

2 tháng 6 2017

a) \(\dfrac{2}{3}x-\dfrac{1}{2}=\dfrac{1}{10}\)

\(\dfrac{2}{3}x=\dfrac{1}{10}+\dfrac{1}{2}=\dfrac{3}{5}\)

\(x=\dfrac{3}{5}:\dfrac{2}{3}=\dfrac{9}{10}\)

b) \(\dfrac{39}{7}:x=13\)

\(x=\dfrac{\dfrac{39}{7}}{13}=\dfrac{3}{7}\)

c) \(\left(\dfrac{14}{5}x-50\right):\dfrac{2}{3}=51\)

\(\dfrac{14}{5}x-50=51\cdot\dfrac{2}{3}=34\)

\(\dfrac{14}{5}x=34+50=84\)

\(x=\dfrac{84}{\dfrac{14}{5}}=30\)

d) \(\left(x+\dfrac{1}{2}\right)\left(\dfrac{2}{3}-2x\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x+\dfrac{1}{2}=0\\\dfrac{2}{3}-2x=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=-\dfrac{1}{2}\\x=\dfrac{1}{3}\end{matrix}\right.\)

e) \(\dfrac{2}{3}x-\dfrac{1}{2}x=\dfrac{5}{12}\)

\(\dfrac{1}{6}x=\dfrac{5}{12}\)

\(x=\dfrac{5}{12}:\dfrac{1}{6}=\dfrac{5}{2}\)

g) \(\left(x\cdot\dfrac{44}{7}+\dfrac{3}{7}\right)\dfrac{11}{5}-\dfrac{3}{7}=-2\)

\(\left(x\cdot\dfrac{44}{7}+\dfrac{3}{7}\right)\cdot\dfrac{11}{5}=-2+\dfrac{3}{7}=-\dfrac{11}{7}\)

\(x\cdot\dfrac{44}{7}+\dfrac{3}{7}=-\dfrac{11}{7}:\dfrac{11}{5}=-\dfrac{5}{7}\)

\(\dfrac{44}{7}x=-\dfrac{5}{7}-\dfrac{3}{7}=-\dfrac{8}{7}\)

\(x=-\dfrac{8}{7}:\dfrac{44}{7}=-\dfrac{2}{11}\)

h) \(\dfrac{13}{4}x+\left(-\dfrac{7}{6}\right)x-\dfrac{5}{3}=\dfrac{5}{12}\)

\(\dfrac{25}{12}x-\dfrac{5}{3}=\dfrac{5}{12}\)

\(\dfrac{25}{12}x=\dfrac{5}{12}+\dfrac{5}{3}=\dfrac{25}{12}\)

\(x=1\)

Mỏi tay woa bn làm nốt nha!!

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DM

Đỗ Minh Quang

18 tháng 4 2020 - olm

Bài 1 Tính nhanh

a) -3/7 + 5/13 + 3/7

b) -5/21+-2/21+8/24

c) -5/11+(-6/11+2)

d) (-1/32+1/2)+15/32

e)5/17+ -6/13 + 3/4 + 7/-13+12/17

f) 7/23+-18/18+-4/9+16/23+-5/8

g)1/3+-3/4+3/5+-1/36+1/15+-2/9

h)-1/2+1/3+-1/4+-2/8+4/18+4/9

#Toán lớp 6

6

DM

Đỗ Minh Quang

18 tháng 4 2020

Ghi đầy đủ nha

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KN

ka nekk

6 tháng 3 2022

bn có thể ghi rõ ràng đc ko?

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NL

nguyen linh chi

23 tháng 1 2020 - olm

tính nhanh

4/5-2/3/+1/5-1/3

2/5 x 7/4 - 2/5x3/7

13/4 x 2/3 x 4/13 x 3/12

75/100 + 18/21 + 19/32 +1/4 + 3/21 + 13/32

2/5 + 6/9+3/4+3/5+1/3+1/4

#Toán lớp 4

3

F

Fudo

23 tháng 1 2020

Bài giải

a, \(\frac{4}{5}-\frac{2}{3}+\frac{1}{5}-\frac{1}{3}\)

\(=\left(\frac{4}{5}+\frac{1}{5}\right)-\left(\frac{2}{3}+\frac{1}{3}\right)=1-1=0\)

b, \(\frac{2}{5}\text{ x }\frac{7}{4}-\frac{2}{5}\text{ x }\frac{3}{7}\)

\(=\frac{2}{5}\text{ x }\left(\frac{7}{4}-\frac{3}{7}\right)=\frac{2}{5}\text{ x }\frac{37}{28}=\frac{37}{70}\)

c, \(\frac{13}{4}\text{ x }\frac{2}{3}\text{ x }\frac{4}{13}\text{ x }\frac{3}{12}=\frac{13\text{ x }2\text{ x }4\text{ x }3}{4\text{ x }3\text{ x }13\text{ x }12}=\frac{1}{6}\)

d, \(\frac{75}{100}+\frac{18}{21}+\frac{19}{32}+\frac{1}{4}+\frac{3}{21}+\frac{13}{32}\)

\(=\frac{3}{4}+\frac{18}{21}+\frac{19}{32}+\frac{1}{4}+\frac{3}{21}+\frac{13}{32}\)

\(=\left(\frac{3}{4}+\frac{1}{4}\right)+\left(\frac{18}{21}+\frac{3}{21}\right)+\left(\frac{19}{32}+\frac{13}{32}\right)\)

\(=1+1+1\)

\(=3\)

e, \(\frac{2}{5}+\frac{6}{9}+\frac{3}{4}+\frac{3}{5}+\frac{1}{3}+\frac{1}{4}\)

\(=\frac{2}{5}+\frac{2}{3}+\frac{3}{4}+\frac{3}{5}+\frac{1}{3}+\frac{1}{4}\)

\(=\frac{1}{5}\left(2+3\right)+\frac{1}{3}\left(2+1\right)+\frac{1}{4}\left(3+1\right)\)

\(=\frac{1}{5}\cdot5+\frac{1}{3}\cdot3+\frac{1}{4}\cdot4\)

\(=1+1+1\)

\(=3\)

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M

Me

23 tháng 1 2020

a, \(\frac{4}{5}-\frac{2}{3}+\frac{1}{5}-\frac{1}{3}\)

\(=\left(\frac{4}{5}+\frac{1}{5}\right)-\left(\frac{2}{3}+\frac{1}{3}\right)=1-1=0\)

b, \(\frac{2}{5}\text{ x }\frac{7}{4}-\frac{2}{5}\text{ x }\frac{3}{7}\)

\(=\frac{2}{5}\text{ x }\left(\frac{7}{4}-\frac{3}{7}\right)=\frac{2}{5}\text{ x }\frac{37}{28}=\frac{37}{70}\)

c, \(\frac{13}{4}\text{ x }\frac{2}{3}\text{ x }\frac{4}{13}\text{ x }\frac{3}{12}=\frac{13\text{ x }2\text{ x }4\text{ x }3}{4\text{ x }3\text{ x }13\text{ x }12}=\frac{1}{6}\)

d, \(\frac{75}{100}+\frac{18}{21}+\frac{19}{32}+\frac{1}{4}+\frac{3}{21}+\frac{13}{32}\)

\(=\frac{3}{4}+\frac{18}{21}+\frac{19}{32}+\frac{1}{4}+\frac{3}{21}+\frac{13}{32}\)

\(=\left(\frac{3}{4}+\frac{1}{4}\right)+\left(\frac{18}{21}+\frac{3}{21}\right)+\left(\frac{19}{32}+\frac{13}{32}\right)\)

\(=1+1+1\)

\(=3\)

e, \(\frac{2}{5}+\frac{6}{9}+\frac{3}{4}+\frac{3}{5}+\frac{1}{3}+\frac{1}{4}\)

\(=\frac{2}{5}+\frac{2}{3}+\frac{3}{4}+\frac{3}{5}+\frac{1}{3}+\frac{1}{4}\)

\(=\frac{1}{5}\left(2+3\right)+\frac{1}{3}\left(2+1\right)+\frac{1}{4}\left(3+1\right)\)

\(=\frac{1}{5}\cdot5+\frac{1}{3}\cdot3+\frac{1}{4}\cdot4\)

\(=1+1+1\)

\(=3\)

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MY

Miuna Yuri

25 tháng 7 2017 - olm

Bài 1: Tính a) -7/9 . 2/3/4 (2/3/4 là hỗn số : 2 là số nguyên, 3/4 là phân số)b) 2/3 + 1/3 . (-2/5)c) 3/4 . 15/1/3 - 3/4 . 43/1/3d) (-49,1) . 13/27 - 58,9 . 13/27e) 0,375 : (-4,5)f) 3/1/7 : (-1/3/7)g) 9/1/3 : 4/2/3 - 2h) (7/3/4 : 0,3125 + 4,5 . 2/2/45) : (-8,5)Bài 2: Tính giá trị biểu thứcA = (-6/11) . 7/10 . (11/-6).(-20)B = (-1/9) . (-17/29) . 58/51C = (-3/7) . 5/11 + (-5/14) . 5/11D = (1/1/27 . 12/23 . 9/14) : (-3/23)Bài 3: Tìm xa) 3/7 . x - 2/5 . x = -17/35b)...

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#Toán lớp 7

2

HH

Huy hoàng indonaca

25 tháng 7 2017

1.

a) \(\frac{-7}{9}.2\frac{3}{4}=\frac{-7}{9}.\frac{11}{4}=\frac{-77}{36}\)

b) \(\frac{2}{3}+\frac{1}{3}.\frac{-2}{5}=\frac{2}{3}+\frac{-2}{15}=\frac{8}{15}\)

c) \(\frac{3}{4}.15\frac{1}{3}-\frac{3}{4}.43\frac{1}{3}=\frac{3}{4}.\frac{46}{3}-\frac{3}{4}.\frac{130}{3}=\frac{23}{2}-\frac{65}{2}=-21\)

d) \(\left(-49,1\right).\frac{13}{27}-58,9.\frac{13}{27}=\frac{13}{27}.\left(-49,1-58,9\right)=\frac{13}{27}.\left(-108\right)=-52\)

e) \(0,375:\left(-4,5\right)=\frac{-1}{12}\)

f) \(3\frac{1}{7}:\left(-1\frac{3}{7}\right)=\frac{22}{7}:\frac{-10}{7}=\frac{-11}{5}\)

g) \(9\frac{1}{3}:4\frac{2}{3}-2=\frac{28}{3}:\frac{14}{3}-2=2-2=0\)

h) \(\left(7\frac{3}{4}:0,3125+4,5.2\frac{2}{45}\right):\left(-8,5\right)=\left(\frac{31}{4}:\frac{5}{16}+\frac{9}{2}.\frac{92}{45}\right):\frac{-17}{2}=\left(\frac{124}{5}+\frac{46}{5}\right):\frac{-17}{2}=34:\frac{-17}{2}=-4\)

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IH

I have a crazy idea

25 tháng 7 2017

Bài 1 : Tính:

a)

\(\frac{-7}{9}.2\frac{3}{4}=\frac{-7}{9}.\frac{11}{4}=\frac{-77}{36}\)

b)

\(\frac{2}{3}+\frac{1}{3}.\frac{-2}{5}=\frac{2}{3}+\frac{-2}{15}=\frac{10}{15}+\frac{-2}{15}=\frac{8}{15}\)

c)

\(\frac{3}{4}.15\frac{1}{3}-\frac{3}{4}.43\frac{1}{3}=\frac{3}{4}.\frac{46}{3}-\frac{3}{4}.\frac{130}{3}\)\(=\frac{23}{2}-\frac{65}{2}=\frac{-42}{2}=-21\)

....

Tự lm tiếp dạng như v

Bài 2 :

\(A=\frac{-6}{11}.\frac{7}{10}.\frac{11}{-6}.-20=\left(\frac{-6}{11}.\frac{11}{-6}\right).\left(\frac{7}{10}.-20\right)\)\(=1.\left(-14\right)=-14\)

.....

Bài 3 :

\(\frac{3}{7}.x-\frac{2}{5}.x=\frac{-17}{35}\)

\(\Leftrightarrow\frac{3}{7}-\frac{2}{5}.x=\frac{-17}{35}\)

\(\Leftrightarrow\frac{1}{35}x=\frac{-17}{35}\)

\(\Leftrightarrow x=\frac{-17}{35}:\frac{1}{35}\)

\(\Leftrightarrow x=\frac{-17}{35}.35=-17\)

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