Tìm $x$, biết: $a)$ $\dfrac{7}{4} x- \dfrac{3}{2}=- \dfrac{4}{5}$ $b)$ $\Big(x- \dfrac{1}{4}\Big)^2= \dfrac{5}{36}-\Big( \dfrac{1}{3}\Big)^2$ $c)$ $- x + \dfrac{3}{2}=x+\dfrac{3}{5}$

Tìm $x$, biết: $a)$ $\dfrac{7}{4} x- \dfrac{3}{2}=- \dfrac{4}{5}$ $b)$ $\Big(x- \dfrac{1}{4}\Big)^2= \dfrac{5}{36}-\Bi...

TD

Thầy Đức Anh

Giáo viên VIP

30 tháng 10 2023 - olm

(1,5 điểm) Tìm $x$, biết:

a) $x+\dfrac{2}{5}=\dfrac{-4}{3}$;

b) $\dfrac{-5}{6}+\dfrac{1}{3} . x=\Big(\dfrac{-1}{2}\Big)^2$;

c) $\dfrac{7}{12}-\Big(x+\dfrac{7}{6}\Big) . \dfrac{6}{5}=\Big(\dfrac{-1}{2}\Big)^3$.

#Toán lớp 7

4

KV

Kiều Vũ Linh

30 tháng 10 2023

a) x + 2/5 = -4/3

x = -4/3 - 2/5

x = -26/15

b) -5/6 + 1/3 x = (-1/2)²

-5/6 + 1/3 x = 1/4

1/3 x = 1/4 + 5/6

1/3 x = 13/12

x = 13/12 : 1/3

x = 13/4

c) 7/12 - (x + 7/6) . 6/5 = (-1/2)³

7/12 - (x + 7/6) . 6/5 = -1/8

(x + 7/6) . 6/5 = 7/12 + 1/8

(x + 7/6) . 6/5 = 17/24

x + 7/6 = 17/24 : 6/5

x + 7/6 = 85/144

x = 85/144 - 7/6

x = -83/144

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NM

Nguyễn Minh Dương

VIP

30 tháng 10 2023

$a,x+\dfrac{2}{5}=-\dfrac{4}{3}\\ \Rightarrow x=-\dfrac{26}{15}\\ b,-\dfrac{5}{6}+\dfrac{1}{3}x=\left(-\dfrac{1}{2}\right)^2\\ \Rightarrow-\dfrac{5}{6}+\dfrac{1}{3}x=\dfrac{1}{4}\\ \Rightarrow\dfrac{1}{3}x=\dfrac{13}{12}\\ \Rightarrow x=\dfrac{13}{4}\\ c,\dfrac{7}{12}-\left(x+\dfrac{7}{6}\right).\dfrac{6}{5}=\left(-\dfrac{1}{2}\right)^3\\ \Rightarrow\dfrac{7}{12}-\left(x+\dfrac{7}{6}\right).\dfrac{6}{5}=-\dfrac{1}{8}\\ \Rightarrow\left(x+\dfrac{7}{6}\right).\dfrac{6}{5}=\dfrac{17}{24}\\ \Rightarrow x+\dfrac{7}{6}=\dfrac{85}{144}\\ \Rightarrow x=-\dfrac{83}{144}.$

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TD

Thầy Đức Anh

Giáo viên VIP

28 tháng 11 2023 - olm

(1,5 điểm) Tìm $x$ biết

a) $\dfrac{3}{4}-\left(x-\dfrac{2}{3}\right)=1 \dfrac{1}{3}$;

b) $\Big| \dfrac{1}{3}-x \Big|=\dfrac{2}{5}$;

c) $\dfrac{x-1}{3}=\dfrac{27}{x-1}$.

#Toán lớp 7

3

KV

Kiều Vũ Linh

28 tháng 11 2023

3/4 - (x - 2/3) = 1 1/3

3/4 - x + 2/3 = 4/3

-x = 4/3 - 3/4 - 2/3

-x = -1/12

x = 1/12

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HY

Hoàng Yến Nhi

28 tháng 11 2023

3/4 - (x - 2/3) = 1 1/3

3/4 - x + 2/3 = 4/3

-x = 4/3 - 3/4 - 2/3

-x = -1/12

x = 1/12

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TD

Thầy Đức Anh

Giáo viên VIP

30 tháng 10 2023 - olm

(1,5 điểm) Tính.

$a)$ $\dfrac{4}{9}+\dfrac{1}{4}$.

$b)$ $\dfrac{1}{3}.\Big( \dfrac{-4}{5} \Big) + \dfrac{1}{3}.\dfrac{-1}{5}$.

$c)$ $\dfrac{1}{5}-\Big[\dfrac{1}{4}-\Big(1-\dfrac{1}{2}\Big)^2\Big]$.

#Toán lớp 7

14

H9

HT.Phong (9A5)

CTVHS

30 tháng 10 2023

a) $\dfrac{4}{9}+\dfrac{1}{4}=\dfrac{25}{36}$

b) $\dfrac{1}{3}\cdot\left(-\dfrac{4}{5}\right)+\dfrac{1}{3}\cdot\left(-\dfrac{1}{5}\right)=\dfrac{1}{3}\cdot\left(-\dfrac{4}{5}-\dfrac{1}{5}\right)=\dfrac{1}{3}\cdot-1=-\dfrac{1}{3}$

c) $\dfrac{1}{5}-\left[\dfrac{1}{4}-\left(1-\dfrac{1}{2}\right)^2\right]=\dfrac{1}{5}-\left[\dfrac{1}{4}-\left(\dfrac{1}{2}\right)^2\right]=\dfrac{1}{5}-\left(\dfrac{1}{4}-\dfrac{1}{4}\right)=\dfrac{1}{5}-0=\dfrac{1}{5}$

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KT

『Kuroba ム Tsuki Ryoo ︵²ᵏ⁷』

30 tháng 10 2023

`#3107.101107`

`a)`

$\dfrac{4}{9}+\dfrac{1}{4}=\dfrac{16}{36}+\dfrac{9}{36}=\dfrac{25}{36}$

`b)`

$\dfrac{1}{3}\cdot\left(\dfrac{-4}{5}\right)+\dfrac{1}{3}\cdot\left(-\dfrac{1}{5}\right)$

$=\dfrac{1}{3}\cdot\left(-\dfrac{4}{5}-\dfrac{1}{5}\right)$

$=\dfrac{1}{3}\cdot\left(-1\right)$

$=-\dfrac{1}{3}$

`c)`

$\dfrac{1}{5}-\left[\dfrac{1}{4}-\left(1-\dfrac{1}{2}\right)^2\right]$

$=\dfrac{1}{5}-\left(\dfrac{1}{4}-\dfrac{1}{4}\right)$

$=\dfrac{1}{5}-0$

$=\dfrac{1}{5}$

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LP

Lê Phương Linh

29 tháng 9 2023 - olm

Tìm x: a) $\dfrac{11}{12}$ - ($\dfrac{2}{5}$ + $\dfrac{3}{4}$x) $\dfrac{2}{3}$ b) $\dfrac{-2}{5}$ + $\dfrac{5}{3}$ . ($\dfrac{3}{2}$ - $\dfrac{4}{15}$x) = $\dfrac{-7}{6}$ c) $\dfrac{1}{2}$ + $\dfrac{3}{4}$x...

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#Toán lớp 7

2

KT

『Kuroba ム Tsuki Ryoo ︵²ᵏ⁷』

29 tháng 9 2023

`#3107`

a)

$\dfrac{11}{12}-\left(\dfrac{2}{5}+\dfrac{3}{4}x\right)=\dfrac{2}{3}?\\ \Rightarrow\dfrac{2}{5}+\dfrac{3}{4}x=\dfrac{11}{12}-\dfrac{2}{3}\\ \Rightarrow\dfrac{2}{5}+\dfrac{3}{4}x=\dfrac{1}{4}\\ \Rightarrow\dfrac{3}{4}x=\dfrac{1}{4}-\dfrac{2}{5}\\ \Rightarrow\dfrac{3}{4}x=-\dfrac{3}{20}\\ \Rightarrow x=-\dfrac{3}{20}\div\dfrac{3}{4}\\ \Rightarrow x=-\dfrac{1}{5}$

Vậy, $x=-\dfrac{1}{5}$

b)

$\dfrac{-2}{5}+\dfrac{5}{3}\cdot\left(\dfrac{3}{2}-\dfrac{4}{15}x\right)=\dfrac{-7}{6}\\ \Rightarrow\dfrac{5}{3}\cdot\left(\dfrac{3}{2}-\dfrac{4}{15}x\right)=\dfrac{-7}{6}-\dfrac{-2}{5}\\ \Rightarrow\dfrac{5}{3}\cdot\left(\dfrac{3}{2}-\dfrac{4}{15}x\right)=-\dfrac{23}{30}\\ \Rightarrow\dfrac{3}{2}-\dfrac{4}{15}x=-\dfrac{23}{30}\div\dfrac{5}{3}\\ \Rightarrow\dfrac{3}{2}-\dfrac{4}{15}x=-\dfrac{23}{50}\\ \Rightarrow\dfrac{4}{15}x=\dfrac{3}{2}-\left(-\dfrac{23}{50}\right)\\ \Rightarrow\dfrac{4}{15}x=\dfrac{49}{25}\\ \Rightarrow x=\dfrac{147}{20}$

Vậy, $x=\dfrac{147}{20}$

c)

$\dfrac{1}{2}+\dfrac{3}{4}x=\dfrac{1}{4}\\ \Rightarrow\dfrac{3}{4}x=\dfrac{1}{4}-\dfrac{1}{2}\\ \Rightarrow\dfrac{3}{4}x=-\dfrac{1}{4}\\ \Rightarrow x=-\dfrac{1}{4}\div\dfrac{3}{4}\\ \Rightarrow x=-\dfrac{1}{3}$

Vậy, $x=-\dfrac{1}{3}.$

$#Emyeu1aithatroi...$

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TM

Trịnh Minh Trí

29 tháng 9 2023

(2/5 + 3/4 . x)= 11/12 -2/3

(2/5 +3/4 . x)= 1/4

3/4 . x = 1/4 - 2/5

3/4 . x = -3/20

x = -3/20 : 3/4

x = -1/5

Vậy .....

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LP

Lê Phương Linh

1 tháng 11 2023 - olm

Tìm x, biết: a) $\dfrac{2}{3}$x - $\dfrac{1}{2}$x = $\left(-\dfrac{7}{12}\right)$ . $1\dfrac{2}{5}$ b) $\left(\dfrac{1}{5}-\dfrac{3}{2}x\right)^2$ = $\dfrac{9}{4}$ c) (1,25 - $\dfrac{4}{5}$x)3 =...

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#Toán lớp 7

2

H9

HT.Phong (9A5)

CTVHS

1 tháng 11 2023

a) $\dfrac{2}{3}x-\dfrac{1}{2}x=\left(-\dfrac{7}{12}\right)\cdot1\dfrac{2}{5}$

$\Rightarrow\dfrac{1}{6}x=\left(-\dfrac{7}{12}\right)\cdot\dfrac{7}{5}$

$\Rightarrow\dfrac{1}{6}x=-\dfrac{49}{60}$

$\Rightarrow x=-\dfrac{49}{60}:\dfrac{1}{6}$

$\Rightarrow x=-\dfrac{49}{10}$

b) $\left(\dfrac{1}{5}-\dfrac{3}{2}x\right)^2=\dfrac{9}{4}$

$\Rightarrow\left(\dfrac{1}{5}-\dfrac{3}{2}x\right)^2=\left(\pm\dfrac{3}{2}\right)^2$

+) $\dfrac{1}{5}-\dfrac{3}{2}x=\dfrac{3}{2}$

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

$\Rightarrow\dfrac{3}{2}x=-\dfrac{13}{10}$

$\Rightarrow x=-\dfrac{13}{10}:\dfrac{3}{2}$

$\Rightarrow x=-\dfrac{13}{15}$

+) $\left(1,25-\dfrac{4}{5}x\right)^3=-125$

$\Rightarrow\left(\dfrac{5}{4}-\dfrac{4}{5}x\right)^3=\left(-5\right)^3$

$\Rightarrow\dfrac{5}{4}-\dfrac{4}{5}x=-5$

$\Rightarrow\dfrac{4}{5}x=\dfrac{5}{4}+5$

$\Rightarrow\dfrac{4}{5}x=\dfrac{25}{4}$

$\Rightarrow x=\dfrac{25}{4}:\dfrac{4}{5}$

$\Rightarrow x=\dfrac{125}{16}$

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NT

Nguyễn Thị Thương Hoài

Giáo viên VIP

1 tháng 11 2023

a, $\dfrac{2}{3}$$x$ - $\dfrac{1}{2}$$x$ = (- $\dfrac{7}{12}$). 1$\dfrac{2}{5}$

$x$.($\dfrac{2}{3}$ - $\dfrac{1}{2}$) = (- $\dfrac{7}{12}$) . $\dfrac{7}{5}$

$x$. $\dfrac{1}{6}$ = - $\dfrac{49}{60}$

$x$ = - $\dfrac{49}{60}$.6

$x$ = -$\dfrac{49}{10}$

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M

Minahana

18 tháng 7 2023

Tìm x,...

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#Toán lớp 7

2

M

Minahana

18 tháng 7 2023

giúp mình giải bài toán trên với. Mình cảm ơn rất nhiều

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NL

Nguyễn Lê Phước Thịnh

22 tháng 7 2023

a: =>1/2x-3/4x=-5/6+7/3

=>-1/4x=14/6-5/6=3/2

=>x=-3/2*4=-6

b: =>4/5x-3/2x=1/2+6/5

=>-7/10x=17/10

=>x=-17/7

c: =>6/5x+6/20=6/5-1/3x

=>6/5x+1/3x=6/5-3/10=12/10-3/10=9/10

=>x=27/46

d: =>6x+3/2+4/5=1/2-2x

=>8x=1/2-3/2-4/5=-1-4/5=-9/5

=>x=-9/40

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LP

Lê Phương Linh

1 tháng 11 2023 - olm

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 - [$\dfrac{17}{2}$ - $\left(\dfrac{-3}{7}+\dfrac{5}{3}\right)$]...

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#Toán lớp 7

2

NT

Nguyễn Thùy Dương

1 tháng 11 2023

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KV

Kiều Vũ Linh

1 tháng 11 2023

a) 1/20 - (x - 8/5) = 1/10

x - 8/5 = 1/20 - 1/10

x - 8/5 = -1/20

x = -1/20 + 8/5

x = 31/20

b) 7/4 - (x + 5/3) = -12/5

x + 5/3 = 7/4 + 12/5

x + 5/3 = 83/20

x = 83/20 - 5/3

x = 149/60

c) x - [17/2 - (-3/7 + 5/3)] = -1/3

x - (17/2 - 26/21) = -1/3

x - 305/42 = -1/3

x = -1/3 + 305/42

x = 97/14

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LP

Lê Phương Linh

12 tháng 9 2023 - olm

a) $2\dfrac{1}{2}$ - x + $\dfrac{4}{5}$ = $\dfrac{2}{3}$ - ($-\dfrac{4}{7}$ ) b) $-\dfrac{4}{7}$ - x = $\dfrac{3}{5}$ - 2x c) ($\dfrac{3}{8}$ - $\dfrac{1}{5}$ ) + ($\dfrac{5}{8}$ - x)...

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#Toán lớp 7

1

NM

Nguyễn Minh Dương

VIP

12 tháng 9 2023

$a,2\dfrac{1}{2}-x+\dfrac{4}{5}=\dfrac{2}{3}-\left(-\dfrac{4}{7}\right)\\ \Rightarrow\dfrac{5}{2}-x+\dfrac{4}{5}=\dfrac{26}{21}\\ \Rightarrow\dfrac{5}{2}-x=\dfrac{46}{105}\\ \Rightarrow x=\dfrac{433}{210}\\ b,-\dfrac{4}{7}-x=\dfrac{3}{5}-2x\\ \Rightarrow2x-\dfrac{4}{7}-x=\dfrac{3}{5}\\ \Rightarrow2x-x=\dfrac{41}{35}\\ \Rightarrow x=\dfrac{41}{35}\\ c,\left(\dfrac{3}{8}-\dfrac{1}{5}\right)+\left(\dfrac{5}{8}-x\right)=\dfrac{1}{5}\\ \Rightarrow\dfrac{7}{40}+\dfrac{5}{8}-x=\dfrac{1}{5}\\ \Rightarrow\dfrac{4}{5}-x=\dfrac{1}{5}\\ \Rightarrow x=\dfrac{3}{5}.$

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TD

Thầy Đức Anh

Giáo viên VIP

27 tháng 4 2022 - olm

Tìm $x$, biết :
a) $-1,62+\dfrac{2}{5}+x=7$
b) $4 \dfrac{3}{5}-x=\dfrac{-1}{5}+\dfrac{1}{2}$
c) $\dfrac{-4}{7}-x=\dfrac{3}{5}-2 x$
d) $\dfrac{5}{7}-\dfrac{1}{13}+0,25=3 \dfrac{1}{2}-x$

#Toán lớp 7

17

T

TINH

13 tháng 7 2022

a) $x=7-\dfrac{2}{5}+1,62=8,22$
b) $\dfrac{3}{5}+\dfrac{1}{5}-\dfrac{1}{2}=4 \dfrac{3}{10}$
c) $x-x=\dfrac{3}{5}+\dfrac{4}{7}$
$x=\dfrac{41}{35}$
d) $\dfrac{1}{2}-\dfrac{5}{7}+\dfrac{1}{13}-0.25$
$\dfrac{223}{364}$

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CT

cohanhNguyễn Thị Quỳnh Trang

31 tháng 7 2022

$x=7-\dfrac{2}{5}+1,62=8,22$
b) $\dfrac{3}{5}+\dfrac{1}{5}-\dfrac{1}{2}=4 \dfrac{3}{10}$
c) $x-x=\dfrac{3}{5}+\dfrac{4}{7}$
$x=\dfrac{41}{35}$
d) $\dfrac{1}{2}-\dfrac{5}{7}+\dfrac{1}{13}-0.25$
$\dfrac{223}{364}$

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