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2 tháng 10 2024

a) \(x-\dfrac{3}{7}=\dfrac{5}{4}\)

\(x=\dfrac{5}{4}+\dfrac{3}{7}\)

\(x=\dfrac{47}{28}\)

b) \(\left(x-\dfrac{3}{5}\right):\dfrac{-1}{3}=0,4\)

\(x-\dfrac{3}{5}=0,4.\dfrac{-1}{3}\)

\(x-\dfrac{3}{5}=-\dfrac{2}{15}\)

\(x=-\dfrac{2}{15}+\dfrac{3}{5}\)

\(x=\dfrac{7}{15}\)

2 tháng 10 2024

a) x= 5/4+3/7

x= 35/28+12/28

x=47/28

b) x-3/5= -0.4/3

x=-0,4/3+3/5 

x= 2/15+9/15

x= 11/15

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

30 tháng 10 2023

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

DT
30 tháng 10 2023

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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

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

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

`#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)`

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

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

\(=\dfrac{1}{5}-0\)

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

13 tháng 7 2022

a) x=7-\dfrac{2}{5}+1,62=8,22x=752+1,62=8,22
b) x=4 \dfrac{3}{5}+\dfrac{1}{5}-\dfrac{1}{2}=4 \dfrac{3}{10}x=453+5121=4103
c) 2 x-x=\dfrac{3}{5}+\dfrac{4}{7}2xx=53+74
x=\dfrac{41}{35}x=3541
d) x=3 \dfrac{1}{2}-\dfrac{5}{7}+\dfrac{1}{13}-0.25x=32175+1310.25
x=2 \dfrac{223}{364}x=2364223

 

 x=7-\dfrac{2}{5}+1,62=8,22x=752+1,62=8,22
b) x=4 \dfrac{3}{5}+\dfrac{1}{5}-\dfrac{1}{2}=4 \dfrac{3}{10}x=453+5121=4103
c) 2 x-x=\dfrac{3}{5}+\dfrac{4}{7}2xx=53+74
x=\dfrac{41}{35}x=3541
d) x=3 \dfrac{1}{2}-\dfrac{5}{7}+\dfrac{1}{13}-0.25x=32175+1310.25
x=2 \dfrac{223}{364}x=2364223
 

a: \(0.4\cdot\sqrt{0.25-\sqrt{\dfrac{1}{4}}}=0.4\cdot\sqrt{0.25-0.5}\)(đề này sai rồi bạn)

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

\(\Leftrightarrow2\left(x-1\right)=\dfrac{-11}{2}-\dfrac{3}{2}=-7\)

\(\Leftrightarrow x-1=\dfrac{-7}{2}\)

hay \(x=-\dfrac{5}{2}\)

20 tháng 9 2023

a, \(\dfrac{3}{7}\)\(x\) - 0,4 = - \(\dfrac{17}{35}\)

    \(\dfrac{3}{7}\)\(x\)         = - \(\dfrac{17}{35}\) + 0,4

     \(\dfrac{3}{7}\)\(x\)       = - \(\dfrac{3}{35}\)

        \(x\)       = - \(\dfrac{3}{35}\)\(\dfrac{3}{7}\)

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

20 tháng 9 2023

b, 0,2.(\(x\) - 3) +2,4 = 10

    0,2.(\(x\) - 3)          = 10 - 2,4

    0,2.(\(x\) - 3)          = 7,6

           \(x\) - 3            = 7,6:0,2

           \(x\) - 3            = 38

            \(x\)                = 38 + 3

             \(x\)                = 41

21 tháng 9 2023

\(a,0,5+\dfrac{1}{3}+0,4+\dfrac{5}{7}-\dfrac{1}{6}-\dfrac{4}{35}\\ =\dfrac{1}{2}+\dfrac{1}{3}+\dfrac{2}{5}+\dfrac{5}{7}-\dfrac{1}{6}-\dfrac{4}{35}\\ =\dfrac{5}{6}+\dfrac{39}{35}-\dfrac{1}{6}-\dfrac{4}{35}\\ =\left(\dfrac{5}{6}-\dfrac{1}{6}\right)+\left(\dfrac{39}{35}-\dfrac{4}{35}\right)\\ =\dfrac{2}{3}+1\\ =\dfrac{4}{3}.\)

\(b,\left(3-\dfrac{1}{4}+\dfrac{2}{3}\right)-\left(5+\dfrac{1}{3}-\dfrac{6}{5}\right)-\left(-6-\dfrac{7}{4}+\dfrac{3}{2}\right)\\ =3-\dfrac{1}{4}+\dfrac{2}{3}-5-\dfrac{1}{3}+\dfrac{6}{5}+6+\dfrac{7}{4}-\dfrac{3}{2}\\ =\left(3-5+6\right)+\left(-\dfrac{1}{4}+\dfrac{7}{4}\right)+\left(\dfrac{2}{3}-\dfrac{1}{3}\right)+\left(\dfrac{6}{5}+\dfrac{7}{4}\right)\\ =4-\dfrac{3}{2}+\dfrac{1}{3}+\dfrac{59}{20}\\ =\dfrac{5}{2}+\dfrac{1}{3}+\dfrac{59}{20}\\ =\dfrac{17}{6}+\dfrac{59}{20}\\ =\dfrac{347}{60}.\)

\(c,\dfrac{1}{3}-\dfrac{3}{4}-\left(-\dfrac{3}{5}\right)+\dfrac{1}{64}-\dfrac{2}{9}-\dfrac{1}{36}+\dfrac{1}{15}\\ =\dfrac{1}{3}+\dfrac{3}{4}+\dfrac{3}{5}+\dfrac{1}{64}-\dfrac{2}{9}-\dfrac{1}{36}+\dfrac{1}{15}\\ =\left(\dfrac{1}{3}-\dfrac{2}{9}\right)+\left(\dfrac{3}{4}-\dfrac{1}{36}\right)+\left(\dfrac{3}{5}+\dfrac{1}{15}\right)+\dfrac{1}{64}\\ =\dfrac{1}{9}+\dfrac{13}{18}+\dfrac{2}{3}+\dfrac{1}{64}\\ =\dfrac{3}{2}+\dfrac{1}{64}\\ =\dfrac{65}{64}.\)

21 tháng 9 2023

câu cuối có sai ko bn?

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.

20 tháng 8 2017

Ths bn nhé

6 tháng 12 2017

B = .................

Xét thừa số 63.1,2 - 21.3,6 = 0 nên B = 0

\(C=\left|\dfrac{4}{9}-\left(\dfrac{\sqrt{2}}{2}\right)^2\right|+\left|0,4+\dfrac{\dfrac{1}{3}-\dfrac{2}{5}-\dfrac{3}{7}}{\dfrac{2}{3}-\dfrac{4}{5}-\dfrac{6}{7}}\right|\)

\(C=\left|\dfrac{4}{9}-\dfrac{1}{2}\right|+\left|0,4+\dfrac{\dfrac{1}{3}-\dfrac{2}{5}-\dfrac{3}{7}}{2\left(\dfrac{1}{3}-\dfrac{2}{5}-\dfrac{3}{7}\right)}\right|\)

\(C=\left|\dfrac{4}{9}-\dfrac{1}{2}\right|+\left|0,4+\dfrac{1}{2}\right|=\dfrac{1}{18}+\dfrac{9}{10}=\dfrac{43}{45}\)

6 tháng 12 2017

Mình làm câu 1,2 trước, câu 3 sau

Câu 1:

\(\sqrt{x^2}=0\)

=> \(\left(\sqrt{x^2}\right)^2=0^2\)

\(\Leftrightarrow x^2=0\Leftrightarrow x=0\)

Câu 2:

\(A=\left(0,75-0,6+\dfrac{3}{7}+\dfrac{3}{12}\right)\left(\dfrac{11}{7}+\dfrac{11}{3}+2,75-2,2\right)\)

\(A=\left(\dfrac{3}{4}-\dfrac{3}{5}+\dfrac{3}{7}+\dfrac{3}{13}\right)\left(\dfrac{11}{7}+\dfrac{11}{3}+\dfrac{11}{4}-\dfrac{11}{5}\right)\)

\(A=3\left(\dfrac{1}{4}-\dfrac{1}{5}+\dfrac{1}{7}+\dfrac{1}{13}\right)\cdot11\left(\dfrac{1}{7}+\dfrac{1}{3}+\dfrac{11}{4}-\dfrac{11}{5}\right)\)

\(A=33\cdot\dfrac{491}{1820}\cdot\dfrac{221}{420}=\dfrac{3580863}{764400}\)