Tìm x, biết : a) $\left(\dfrac{31}{20}-\dfrac{26}{45}\right).\dfrac{-36}{35}< x< \left(\dfrac{51}{56} \dfrac{8}{21} \dfrac{1}{3}\right).\dfrac{8}{13}$ b) $\dfrac{-3}{5}.x=\dfrac{1}{4} 0,75$...

NT

Nguyễn Thu Thảo

15 tháng 3 2017

Tìm x, biết : a) $\left(\dfrac{31}{20}-\dfrac{26}{45}\right).\dfrac{-36}{35} x \left(\dfrac{51}{56}+\dfrac{8}{21}+\dfrac{1}{3}\right).\dfrac{8}{13}$ b) $\dfrac{-3}{5}.x=\dfrac{1}{4}+0,75$ c) $\left(\dfrac{1}{7}-\dfrac{1}{3}\right).x=\dfrac{28}{3}.\left(\dfrac{1}{4}-\dfrac{1}{7}\right)$ d) $\dfrac{5}{7}.x=\dfrac{9}{8}-0,125$ ...

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#Toán lớp 6

2

HT

Hoàng Thị Ngọc Anh

15 tháng 3 2017

Mấy bài này bạn tự làm đi, chuyển vế tìm x gần giống cấp I mà.

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KW

Karry Wang

20 tháng 3 2017

b)$\dfrac{-3}{5}.x=\dfrac{1}{4}+0,75$

=>$\dfrac{-3}{5}.x=1$

=>$x=1:\dfrac{-3}{5}$

=>$x=\dfrac{-5}{3}$

Vậy $x=\dfrac{-5}{3}$

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NH

Nguyễn Hữu Bình

23 tháng 3 2022

Tìm số nguyên x, biết: ( $\dfrac{31}{20}-\dfrac{26}{45}$ ) . $\dfrac{-36}{35}< x< \left(\dfrac{51}{56}+\dfrac{8}{21}+\dfrac{1}{3}\right).\dfrac{8}{13}$

#Toán lớp 6

3

CQ

cun quynh

23 tháng 3 2022

????????????????

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HH

Hồ Hoàng Khánh Linh

23 tháng 3 2022

mik còn chx hc nx

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NT

Nguyễn Trịnh Diệu Linh

4 tháng 3 2018

Bài 1 : Tìm các số nguyên x , biết : a) $\dfrac{2}{3}\left(\dfrac{1}{2}+\dfrac{3}{4}-\dfrac{1}{3}\right)\le\dfrac{x}{18}\le\dfrac{7}{13}\left(\dfrac{1}{2}-\dfrac{1}{6}\right)$ b) $\left(\dfrac{31}{20}-\dfrac{26}{45}\right).-\dfrac{36}{35} x \left(\dfrac{51}{56}+\dfrac{8}{21}+\dfrac{1}{3}\right).\dfrac{8}{13}$ Bài 2 : C =...

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#Toán lớp 6

1

NL

Nguyễn Lê Phước Thịnh

23 tháng 6 2022

Bài 1:

a: $\Leftrightarrow\dfrac{2}{3}\cdot\dfrac{6+9-4}{12}< =\dfrac{x}{18}< =\dfrac{7}{13}\cdot\dfrac{3-1}{6}$

$\Leftrightarrow\dfrac{22}{36}< =\dfrac{x}{18}< =\dfrac{14}{78}=\dfrac{7}{39}$

$\Leftrightarrow\dfrac{11}{9}< =\dfrac{x}{9}< =\dfrac{7}{13}$

=>143<=x<=63

hay $x\in\varnothing$

b: $\Leftrightarrow\dfrac{31\cdot9-26\cdot4}{180}\cdot\dfrac{-36}{35}< x< \dfrac{153+64+56}{168}\cdot\dfrac{8}{13}$

$\Leftrightarrow-1< x< 1$

=>x=0

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NT

Nguyễn Thế Dương

22 tháng 3 2021

a) Tìm tập hợp các số nguyên x, biết rằng$4\dfrac{5}{9}:2\dfrac{5}{18}-7 x \left(3\dfrac{1}{5}:3,2+4,5.1\dfrac{31}{45}\right):\left(-21\dfrac{1}{2}\right)$b) tìm x, biết $\left|x+\dfrac{1}{2}\right|+\left|x+\dfrac{1}{6}\right|+\left|x+\dfrac{1}{12}\right|+\left|x+\dfrac{1}{20}\right|+....+\left|x+\dfrac{1}{110}\right|-11x$c)Tính gt biểu thức $C=2x^3-5y^3+2015$ tại x,y thỏa...

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#Toán lớp 7

0

HN

Hang Nguyen

22 tháng 7 2021

bài 3 thực hiện phép tínha$\dfrac{5}{8}+\dfrac{3}{17}+\dfrac{4}{18}+\dfrac{20}{-17}+\dfrac{-2}{9}+\dfrac{21}{56}$b$\left(\dfrac{9}{16}+\dfrac{8}{-27}\right)+\left(1+\dfrac{7}{16}+\dfrac{-19}{27}\right)$c$\left(\dfrac{13}{5}+\dfrac{7}{16}\right)+\left(\dfrac{-15}{16}+\dfrac{6}{15}\right)$ ...

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#Toán lớp 6

1

NL

Nguyễn Lê Phước Thịnh

22 tháng 7 2021

a) Ta có: $\dfrac{5}{8}+\dfrac{3}{17}+\dfrac{4}{18}+\dfrac{20}{-17}+\dfrac{-2}{9}+\dfrac{21}{56}$

$=\left(\dfrac{3}{17}-\dfrac{20}{17}\right)+\left(\dfrac{2}{9}-\dfrac{2}{9}\right)+\left(\dfrac{5}{8}+\dfrac{3}{8}\right)$

$=-1+1=0$

b) Ta có: $\left(\dfrac{9}{16}+\dfrac{8}{-27}\right)+\left(1+\dfrac{7}{16}+\dfrac{-19}{27}\right)$

$=\left(\dfrac{9}{16}+\dfrac{7}{16}\right)+\left(\dfrac{-8}{27}-\dfrac{19}{27}\right)+1$

=1-1+1=1

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HN

Hồ Ngọc Bảo Nam

22 tháng 7 2021

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LT

Lê Thị Ngọc Duyên

20 tháng 8 2017

ĐỀ 1: 1. Tính: a. $\dfrac{7}{23}\left[\left(\dfrac{-8}{6}\right)-\dfrac{45}{18}\right]$ b. $\dfrac{1}{5}:\dfrac{1}{10}-\dfrac{1}{3}\left(\dfrac{6}{5}-\dfrac{9}{4}\right)$ c. $\dfrac{3}{5}.\left(\dfrac{-8}{3}\right)-\dfrac{3}{5}:\left(-6\right)$ d. $\dfrac{1}{2}\left(\dfrac{4}{3}+\dfrac{2}{5}\right)-\dfrac{3}{4}\left(\dfrac{8}{9}+\dfrac{16}{3}\right)$ e. $\dfrac{6}{7}:\left(\dfrac{3}{26}-\dfrac{3}{13}\right)+\dfrac{6}{7}\left(\dfrac{1}{10}-\dfrac{8}{5}\right)$ 2. Tìm x,...

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#Toán lớp 7

1

TT

Thanh Trà

20 tháng 8 2017

1.Tính

a.$\dfrac{7}{23}\left[(-\dfrac{8}{6})-\dfrac{45}{18}\right]=\dfrac{7}{23}.-\dfrac{12}{6}=-\dfrac{7}{6}$

b.$\dfrac{1}{5}\div\dfrac{1}{10}-\dfrac{1}{3}(\dfrac{6}{5}-\dfrac{9}{4})=2-(-\dfrac{7}{20})=\dfrac{47}{20}$

c.$\dfrac{3}{5}.(-\dfrac{8}{3})-\dfrac{3}{5}\div(-6)=-\dfrac{3}{2}$

d.$\dfrac{1}{2}.(\dfrac{4}{3}+\dfrac{2}{5})-\dfrac{3}{4}.(\dfrac{8}{9}+\dfrac{16}{3})=-\dfrac{19}{5}$

e.$\dfrac{6}{7}\div(\dfrac{3}{26}-\dfrac{3}{13})+\dfrac{6}{7}.(\dfrac{1}{10}-\dfrac{8}{5})=-\dfrac{61}{7}$

Bài 2

a.$1^2_5x+\dfrac{3}{7}=\dfrac{4}{5}$

$x=\dfrac{13}{49}$

b.$\left|x-1,5\right|=2$

Xảy ra 2 trường hợp

TH1

$x-1,5=2$

$x=3,5$

TH2

$x-1,5=-2$

$x=-0,5$

Vậy $x=3,5$ hoặc $x=-0,5$ .

Ngại làm quá trời ơi,lần sau bn tách ra nhá làm vậy mỏi tay quá.

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LT

Lê Thị Ngọc Duyên

20 tháng 8 2017

Ths bn nhé

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NT

Nguyễn Thu Huyền

1 tháng 9 2023

Tìm...

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#Toán lớp 7

3

T

Toru

1 tháng 9 2023

$a,3-x=x+1,8$

$\Rightarrow-x-x=1,8-3$

$\Rightarrow-2x=-1,2$

$\Rightarrow x=0,6$

$b,2x-5=7x+35$

$\Rightarrow2x-7x=35+5$

$\Rightarrow-5x=40$

$\Rightarrow x=-8$

$c,2\left(x+10\right)=3\left(x-6\right)$

$\Rightarrow2x+20=3x-18$

$\Rightarrow2x-3x=-18-20$

$\Rightarrow-x=-38$

$\Rightarrow x=38$

$d,8\left(x-\dfrac{3}{8}\right)+1=6\left(\dfrac{1}{6}+x\right)+x$

$\Rightarrow8x-3+1=1+6x+x$

$\Rightarrow8x-3=7x$

$\Rightarrow8x-7x=3$

$\Rightarrow x=3$

$e,\dfrac{2}{9}-3x=\dfrac{4}{3}-x$

$\Rightarrow-3x+x=\dfrac{4}{3}-\dfrac{2}{9}$

$\Rightarrow-2x=\dfrac{10}{9}$

$\Rightarrow x=-\dfrac{5}{9}$

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T

Toru

1 tháng 9 2023

$g,\dfrac{1}{2}x+\dfrac{5}{6}=\dfrac{3}{4}x-\dfrac{1}{2}$

$\Rightarrow\dfrac{1}{2}x-\dfrac{3}{4}x=-\dfrac{1}{2}-\dfrac{5}{6}$

$\Rightarrow-\dfrac{1}{4}x=-\dfrac{4}{3}$

$\Rightarrow x=\dfrac{16}{3}$

$h,x-4=\dfrac{5}{6}\left(6-\dfrac{6}{5}x\right)$

$\Rightarrow x-4=5-x$

$\Rightarrow x+x=5+4$

$\Rightarrow2x=9$

$\Rightarrow x=\dfrac{9}{2}$

$k,7x^2-11=6x^2-2$

$\Rightarrow7x^2-6x^2=-2+11$

$\Rightarrow x^2=9\Rightarrow\left[{}\begin{matrix}x=3\\x=-3\end{matrix}\right.$

$m,5\left(x+3\cdot2^3\right)=10^2$

$\Rightarrow5\left(x+24\right)=100$

$\Rightarrow x+24=20$

$\Rightarrow x=-4$

$n,\dfrac{4}{9}-\left(\dfrac{1}{6^2}\right)=\dfrac{2}{3}\left(x-\dfrac{2}{3}\right)^2+\dfrac{5}{12}$

$\Rightarrow\dfrac{2}{3}\left(x-\dfrac{2}{3}\right)^2+\dfrac{5}{12}=\dfrac{4}{9}-\dfrac{1}{36}$

$\Rightarrow\dfrac{2}{3}\left(x-\dfrac{2}{3}\right)^2+\dfrac{5}{12}=\dfrac{5}{12}$

$\Rightarrow\dfrac{2}{3}\left(x-\dfrac{2}{3}\right)^2=0$

$\Rightarrow x-\dfrac{2}{3}=0\Rightarrow x=\dfrac{2}{3}$

#$Urushi\text{☕}$

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LT

luong thi kim anh

3 tháng 9 2021

Tìm x biết:

a) x-$\dfrac{2}{3}$=$\dfrac{3}{8}$ b) x-$\dfrac{3}{4}$=$\dfrac{13}{10}$:$\dfrac{26}{5}$ c) $\dfrac{3}{2}$-$\left(x+\dfrac{1}{2}\right)$=$\dfrac{4}{5}$ d) |x-2|-1=0

#Toán lớp 7

2

LL

Lấp La Lấp Lánh

3 tháng 9 2021

a) $x-\dfrac{2}{3}=\dfrac{3}{8}\Rightarrow x=\dfrac{3}{8}+\dfrac{2}{3}=\dfrac{25}{24}$

b) $x-\dfrac{3}{4}=\dfrac{13}{10}:\dfrac{26}{5}\Rightarrow x-\dfrac{3}{4}=\dfrac{1}{4}\Rightarrow x=\dfrac{1}{4}+\dfrac{3}{4}=1$

c) $\dfrac{3}{2}-\left(x+\dfrac{1}{2}\right)=\dfrac{4}{5}\Rightarrow x+\dfrac{1}{2}=\dfrac{3}{2}-\dfrac{4}{5}=\dfrac{7}{10}$

$\Rightarrow x=\dfrac{7}{10}-\dfrac{1}{2}=\dfrac{1}{5}$

d) $\left|x-2\right|-1=0\Rightarrow\left|x-2\right|=1$

$\Rightarrow\left[{}\begin{matrix}x-2=1\\x-2=-1\end{matrix}\right.$$\Rightarrow\left[{}\begin{matrix}x=3\\x=1\end{matrix}\right.$

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NL

Nguyễn Lê Phước Thịnh

3 tháng 9 2021

a: Ta có: $x-\dfrac{2}{3}=\dfrac{3}{8}$

$\Leftrightarrow x=\dfrac{3}{8}+\dfrac{2}{3}=\dfrac{9}{24}+\dfrac{16}{24}=\dfrac{25}{24}$

b: Ta có: $x-\dfrac{3}{4}=\dfrac{13}{10}:\dfrac{26}{5}$

$\Leftrightarrow x-\dfrac{3}{4}=\dfrac{13}{10}\cdot\dfrac{5}{26}=\dfrac{1}{4}$

hay x=1

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TD

Thầy Đức Anh

Giáo viên VIP

27 tháng 4 2022 - olm

Tìm $x$, biết :
a) $\left(\dfrac{1}{2}+1,5\right) \cdot x=\dfrac{1}{5}$
b) $\left(-1 \dfrac{3}{5}+x\right): \dfrac{12}{13}=2 \dfrac{1}{6}$
c) $\left(x: 2 \dfrac{1}{3}\right) \cdot \dfrac{1}{7}=\dfrac{-3}{8}$
d) $\dfrac{-4}{7} \cdot x+\dfrac{7}{5}=\dfrac{1}{8}:\left(-1 \dfrac{2}{3}\right)$

#Toán lớp 7

13

YN

Yen Nhi

21 tháng 6 2022

$a)\left(\dfrac{1}{2}+1,5\right)x=\dfrac{1}{5}$

$\Rightarrow2x=\dfrac{1}{5}$

$\Rightarrow x=\dfrac{1}{10}$

$b)\left(-1\dfrac{3}{5}+x\right):\dfrac{12}{13}=2\dfrac{1}{6}$

$\Leftrightarrow-\dfrac{8}{5}+x=\dfrac{13}{6}.\dfrac{12}{13}$

$\Leftrightarrow-\dfrac{8}{5}+x=2$

$\Leftrightarrow x=\dfrac{18}{5}$

$c)\left(x:2\dfrac{1}{3}\right).\dfrac{1}{7}=-\dfrac{3}{8}$

$\Leftrightarrow x:\dfrac{7}{3}=-\dfrac{3}{8}:\dfrac{1}{7}$

$\Leftrightarrow x=-\dfrac{21}{8}.\dfrac{7}{3}$

$\Leftrightarrow x=-\dfrac{49}{8}$

$d)-\dfrac{4}{7}x+\dfrac{7}{5}=\dfrac{1}{8}:\left(-1\dfrac{2}{3}\right)$

$\Leftrightarrow-\dfrac{4}{7}x+\dfrac{7}{5}=-\dfrac{3}{40}$

$\Leftrightarrow-\dfrac{4}{7}x=-\dfrac{59}{40}$

$\Leftrightarrow x=\dfrac{413}{160}$

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T

TINH

13 tháng 7 2022

a) $\left(\dfrac{1}{2}+1,5\right) \cdot x=\dfrac{1}{5}$

$\cdot x=\dfrac{1}{5}$

$x=\dfrac{1}{5}: 2$

$x=\dfrac{1}{10}$
b) $\left(-1 \dfrac{3}{5}+x\right): \dfrac{12}{13}=2 \dfrac{1}{6}$

$\dfrac{3}{5}+x=\dfrac{13}{6} \cdot \dfrac{12}{13}$
$\dfrac{3}{5}$

$\dfrac{3}{5}$
c) $\left(x: 2 \dfrac{1}{3}\right) \cdot \dfrac{1}{7}=\dfrac{-3}{8}$

$\cdot \dfrac{3}{7} \cdot \dfrac{1}{7}=\dfrac{-3}{8}$

$x=\dfrac{-3}{8}: \dfrac{3}{49}$
$x=\dfrac{-49}{8}=-6 \dfrac{1}{8}$
d) $\dfrac{-4}{7} \cdot x+\dfrac{7}{5}=\dfrac{1}{8}:\left(-1 \dfrac{2}{3}\right)$

$\dfrac{-4}{7} x+\dfrac{7}{5}=\dfrac{1}{8} \cdot \dfrac{-3}{5}$
$-\dfrac{4}{7} x=\dfrac{-3}{40}-\dfrac{7}{5} \\ x=\dfrac{-59}{40}: \dfrac{-4}{7}=\dfrac{413}{160}=2 \dfrac{93}{160}$

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TG

Thunder Gaming

20 tháng 7 2018

Tính hợp lý: a, $\dfrac{-3}{4}.5\dfrac{3}{13}-0,75.\dfrac{36}{13}$ b, $4\dfrac{5}{9}:\left(\dfrac{-5}{7}\right)+\dfrac{49}{9}:\left(\dfrac{-5}{7}\right)$ c, $\left(\dfrac{-3}{5}+\dfrac{4}{9}\right):\dfrac{7}{11}+\left(\dfrac{-2}{5}+\dfrac{5}{9}\right):\dfrac{7}{11}$ d, $\dfrac{6}{7}:\left(\dfrac{3}{26}-\dfrac{3}{13}\right)+\dfrac{6}{7}:\left(\dfrac{1}{10}-\dfrac{8}{5}\right)$ ...

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#Toán lớp 7

2

V

Vivian

21 tháng 7 2018

*Trả lời :

a) $-\dfrac{3}{4}.5\dfrac{3}{13}-0,75.\dfrac{36}{13}$

= $-\dfrac{3}{4}.\dfrac{68}{13}-\dfrac{3}{4}.\dfrac{36}{13}$

=$\dfrac{3}{4}.\dfrac{-68}{13}-\dfrac{3}{4}.\dfrac{36}{13}$

=$\dfrac{3}{4}.\cdot\left(\dfrac{-68}{13}-\dfrac{36}{13}\right)$

=$\dfrac{3}{4}.\left(-8\right)$

= $-6$

b)$4\dfrac{5}{9}:\left(-\dfrac{5}{7}\right)+\dfrac{49}{9}:\left(-\dfrac{5}{7}\right)$

=$\dfrac{41}{9}-\left(-\dfrac{5}{7}\right)+\dfrac{49}{9}:\left(-\dfrac{5}{7}\right)$

=$\left(\dfrac{41}{9}+\dfrac{49}{9}\right):\left(-\dfrac{5}{7}\right)$

=$\dfrac{90}{9}:\left(-\dfrac{5}{7}\right)$

=$10:\left(-\dfrac{5}{7}\right)$

=$-14$

c)$\left(-\dfrac{3}{5}+\dfrac{4}{9}\right):\dfrac{7}{11}+\left(-\dfrac{2}{5}+\dfrac{5}{9}\right):\dfrac{7}{11}$

=$\left(-\dfrac{3}{5}\right)+\dfrac{4}{9}:\dfrac{7}{11}+\left(-\dfrac{2}{5}\right)+\dfrac{5}{9}:\dfrac{7}{11}$(áp dụng tính chất phá ngoặc )

=$\left\{\left[-\dfrac{3}{5}+\left(-\dfrac{2}{5}\right)\right]+\left(\dfrac{4}{9}+\dfrac{5}{9}\right)\right\}:\dfrac{7}{11}$

=$\left(-\dfrac{5}{5}+\dfrac{9}{9}\right):\dfrac{7}{11}$

=$\left(-1+1\right):\dfrac{7}{11}$

$=0:\dfrac{7}{11}$

=0.

d)$\dfrac{6}{7}:\left(\dfrac{3}{26}-\dfrac{3}{13}\right)+\dfrac{6}{7}:\left(\dfrac{1}{10}-\dfrac{8}{5}\right)$

=$\dfrac{6}{7}:\left[\dfrac{3}{26}+\left(-\dfrac{6}{26}\right)\right]+\dfrac{6}{7}:\left[\dfrac{1}{10}+\left(-\dfrac{16}{10}\right)\right]$

=$\dfrac{6}{7}:\left(-\dfrac{3}{26}\right)+\dfrac{6}{7}:\left(-\dfrac{3}{2}\right)$

=$\dfrac{6}{7}:\left[\left(-\dfrac{3}{26}\right)+\left(-\dfrac{39}{26}\right)\right]$

=$\dfrac{6}{7}:\left(-\dfrac{21}{13}\right)$

=$-\dfrac{26}{49}$

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CT

Chú Thỏ Xinh Xắn

22 tháng 7 2018

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