=5.(1+1/23+1/27+1/2018)

_______________________=5/7

7.(1+1/23+1/27+1/2018)

giúp mình với

\(\frac{5.\left(1+\frac{1}{23}+\frac{1}{27}+\frac{1}{2018}\right)}{7.\left(1+\frac{1}{23}+\frac{1}{27}+\frac{1}{2018}\right)}\)

=5/7

`#3107.101107`

\(3\left(x-32\right)-7=23\cdot5-50\)

\(\Rightarrow3\left(x-32\right)-7=115-50\)

\(\Rightarrow3\left(x-32\right)-7=65\)

\(\Rightarrow3\left(x-32\right)=65+7\)

\(\Rightarrow3\left(x-32\right)=72\)

\(\Rightarrow x-32=72\div3\)

\(\Rightarrow x-32=24\)

\(\Rightarrow x=24+32\)

\(\Rightarrow x=56\)

Vậy, `x = 56.`

\(3\left(x-32\right)-7=23.5-50\)

\(3\left(x-32\right)-7=115-50\)

\(3\left(x-32\right)-7=65\)

\(3\left(x-32\right)=65+7\)

\(3\left(x-32\right)=72\)

\(x-32=72:3\)

\(x-32=24\)

\(x=24+32\)

\(x=56\)

giúp mình vs

a; \(\dfrac{9}{27}\) + \(\dfrac{7}{-49}\)

= \(\dfrac{1}{3}\) - \(\dfrac{1}{7}\)

= \(\dfrac{7}{21}\) - \(\dfrac{3}{21}\)

= \(\dfrac{4}{21}\)

b; - \(\dfrac{12}{10}\) + \(\dfrac{-25}{30}\)

   =  - \(\dfrac{6}{5}\) - \(\dfrac{5}{6}\)

   = -\(\dfrac{36}{30}\) - \(\dfrac{25}{30}\)

  = \(\dfrac{-61}{30}\) 

c; \(\dfrac{-20}{35}\) + \(\dfrac{-16}{-24}\)

 =  - \(\dfrac{4}{7}\) + \(\dfrac{2}{3}\)

= - \(\dfrac{12}{21}\) + \(\dfrac{14}{21}\)

=  \(\dfrac{2}{21}\)

d; - \(\dfrac{21}{77}\) + \(\dfrac{10}{-35}\)

 = - \(\dfrac{3}{11}\) - \(\dfrac{2}{7}\)

 = - \(\dfrac{21}{77}\) -  \(\dfrac{22}{77}\)

= - \(\dfrac{43}{77}\)

a)  >

b) > 

c) >   

d) < 

Ta có:  23.5 ⋮ 5 ; 70 ⋮ 5 .

Để  x + 23.5 + 70 ⋮ 5  thì x phải chia hết cho 5 .

Trong các đáp án có  75 ⋮ 5 .

Vậy 75 là đáp án đúng. 

`@` `\text {Ans}`

`\downarrow`

`1)`

`5/7*37 13/23 - 51 13/23*5/7`

`= 5/7* (37 13/23 - 51 13/23)`

`= 5/7* (-14)`

`= -10`

`2)`

`-2/3 +1/3+0,5+2 1/2`

`= -2/3 + 1/3 + 1/2 + 5/2`

`= (-2/3+1/3) + (1/2+5/2)`

`= -1/3 + 3`

`=8/3`

`3)`

`-0,5+2/3+1/2`

`= -1/2 + 2/3 + 1/2`

`= (-1/2 + 1/2) + 2/3`

`= 2/3`

`4)`

`(8+2 1/3-3/5) -(5+0,4)-(3 1/2 -2)`

`= 8+ 7/3 - 3/5 - 5 - 0,4 - 7/2 + 2`

`= (8+2-5) + (-3/5 - 2/5) + (7/3 - 7/2)`

`= 5 - 1 - 7/6`

`= 4 - 7/6 = 17/6`

`5)`

`(2/9-7/12):3/4+(16/9-5/12):3/4`

`= (2/9 - 7/12) \times 4/3 + (16/9 - 5/12) \times 4/3`

`= 4/3 *(2/9 - 7/12 + 16/9 - 5/12)`

`= 4/3 * [(2/9 + 16/9) + (-7/12 - 5/12)]`

`= 4/3 * ( 2 - 1)`

`= 4/3 * 1 = 4/3`

`6)`

`-(2021.0,7+19,75) +0,7- (8-19,75)`

`= -2021*0,7 -19,75 + 0,7 - 8 + 19,75`

`= 0,7*(-2021 + 1) - 8`

`= -1414-8`

`= -1422`

`7)`

`15/34+7/21+19/34-20/15`

`= (15/34 + 19/34) + 7/21 - 20/15`

`= 1 + 7/21 - 20/15`

`= 4/3 - 20/15 =0`

`8)`

`2 5/6+1/6:(-5/8)`

`= 17/6 + (-4/15)`

`= 77/30`

`9)`

`(-2)^2 +2/9. (4/5-2/3)`

`= 4 + 2/9*2/15`

`= 4+4/135`

`= 544/135`

`10)`

`(-1/5+3/7):5/4+(-4/5+4/7):5/4`

`= (-1/5+3/7) * 4/5 + (-4/5+4/7) * 4/5`

`= 4/5*(-1/5 +3/7-4/5+4/7)`

`= 4/5*[(-1/5-4/5)+(3/7+4/7)]`

`= 4/5* (-1+1)`

`= 4/5*0=0`

`11)`

`2022,2021 . 1954,1945+ 2022,2021 . (-1954,1945)`

`= 2022,2021 * [1954,1945 + (-1954,1945)]`

`= 2022,2021*0 `

`= 0`

`12)`

`-5,2 .72 +69,1 +5,2 . (-28)+(-1,1)`

`= -5,2*72 + 69,1 - 5,2*28 - 1,1`

`= -5,2*(72+28) + (69,1 - 1,1)`

`= -5,2*100 + 68`

`= -520 + 68`

`= -452`

`13)`

`(7 -1/2-3/4) : (5-1/4-5/8)`

`= 23/4 \div 33/8`

`=46/33`

`14)`

`(8+ 2 1/3 -3/5) -(5+0,4) -( 3 1/3 - 2)`

`= 8+ 2 1/3 - 3/5 - 5 - 0,4 - 3 1/3 + 2`

`= (8+2-5) + (2 1/3 - 3 1/3) - (0,6 + 0,4) `

`= 5 - 1 - 1`

`= 3`

help lười tính quá

2: \(=\dfrac{-1}{3}+3=\dfrac{8}{3}\)

3: =1/2-1/2+2/3=2/3

5: \(=\dfrac{4}{3}\left(\dfrac{2}{9}-\dfrac{7}{12}+\dfrac{16}{9}-\dfrac{5}{12}\right)=\dfrac{4}{3}\)

12: \(=5.2\left(-72-28\right)+68=-520+68=-452\)

13: \(\dfrac{23}{4}:\dfrac{33}{8}=\dfrac{46}{33}\)

a: =>41-(2x-5)=720:40=18

=>2x-5=23

=>2x=28

=>x=14

b: =>100x+5050=5750

=>100x=700

=>x=7

a: =>41-(2x-5)=720:40=18

=>2x-5=23

=>2x=28

=>x=14

b: =>100x+5050=5750

=>100x=700

=>x=7

\(\left(25\cdot21+25\cdot51\right):36\\ =\left[25\cdot\left(21+51\right)\right]:36\\ =\left(25\cdot72\right):36\\ =1800:36\\ =50\\ \left\{188-\left[33+\left(6^2-7\cdot3\right)\right]\right\}:70\\ =\left\{188-\left[33+\left(36-21\right)\right]\right\}:70\\ =\left[188-\left(33+15\right)\right]:70\\ =\left(188-48\right):70\\ =140:70\\ =2\)

\(\left(x-1\right)\left(15-3x\right)=0\\ \Rightarrow\left[{}\begin{matrix}x-1=0\\15-3x=0\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=1\\3x=15\end{matrix}\right.\\ \Leftrightarrow\left[{}\begin{matrix}x=1\\x=5\end{matrix}\right.\)

\(720:\left[41-\left(2x+5\right)\right]=2^3\cdot5=8\cdot5\\ \Rightarrow720:\left[41-\left(2x+5\right)\right]=40\\ \Rightarrow41-\left(2x+5\right)=720:40\\ \Rightarrow41-\left(2x+5\right)=18\\ \Rightarrow2x+5=41-18\\ \Rightarrow2x+5=23\\ \Rightarrow2x=23-5\\ \Rightarrow2x=18\\ \Rightarrow x=18:2\\ \Rightarrow x=9\)

a) (25.21 + 25.51) : 36

= [ 25.( 21 + 51 ) ] : 36

= [ 25. 72 ] : 36

= 1800 : 36

= 50.