a) 71 - (33 + x) = 26

⇔ 71 - 33 - x = 26

⇔ 38 - x = 26

⇔ x = 38 - 26

⇔ x = 12

b) (x + 73) - 26 = 76

⇔ x + 73 - 26 = 76

⇔ x + 47 = 76

⇔ x = 76 - 47

⇔ x = 29

c) 45 - (x + 9) = 6

⇔ 45 - x - 9 = 6

⇔ 36 - x = 6

⇔ x = 36 - 6

⇔ x = 30

d) 89 - (73 - x) = 20

⇔ 89 - 73 + x = 20

⇔ 16 + x = 20

⇔ x = 20 - 16

⇔ x = 4

e) (x + 7) - 25 = 13

⇔ x + 7 - 25 = 13

⇔ x - 18 = 13

⇔ x = 13 + 18

⇔ x = 31

f) 198 - (x + 4) = 120

⇔ 198 - x - 4 = 120

⇔ 194 - x = 120

⇔ x = 194 - 120

⇔ x = 74

g) 140 : (x - 8) = 7

⇔ x - 8 = 140 : 7

⇔ x - 8 = 20

⇔ x = 20 + 8

⇔ x = 28

h) 4(x + 41) = 400

⇔ x + 41 = 400 : 4

⇔ x + 41 = 100

⇔ x = 100 - 41

⇔ x = 59

i) 11(x - 9) = 77

⇔ x - 9 = 77 : 11

⇔ x - 9 = 7

⇔ x = 7 + 9

⇔ x = 16

j) 5(x - 9) = 350

⇔ x - 9 = 350 : 5

⇔ x - 9 = 70

⇔ x = 70 + 9

⇔ x = 79

k) 2x - 49 = 5.3²

⇔ 2x - 49 = 45

⇔ 2x = 45 + 49

⇔ 2x = 94

⇔ x = 94 : 2

⇔ x = 47

l) 200 - (2x + 6) = 4³

⇔ 200 - 2x - 6 = 64

⇔ 194 - 2x = 64

⇔ 2x = 194 - 64

⇔ 2x = 130

⇔ x = 130 : 2

⇔ x = 65

a) 71 - (33 + x) = 26

⇔ 33+x=71-26

⇔ 33 + x = 45

⇔ x = 45 - 33

⇔ x = 12

Vậy x=12

b) (x + 73) - 26 = 76

⇔ (x + 73) = 76+26

⇔ x + 73 = 102

⇔ x = 102-73

⇔ x = 29

Vậy x=29

c) 45 - (x + 9) = 6

⇔ x + 9 = 45 - 6

⇔ x+9 = 39

⇔ x = 39 - 9

⇔ x = 30

Vậy x=30

d) 89 - (73 - x) = 20

⇔ 73 - x = 89 - 20

⇔ 73 - x = 69

⇔ x = 73 - 69

⇔ x = 4

Vậy x=4

e) (x + 7) - 25 = 13

⇔ x + 7 = 13 + 25

⇔ x + 7 = 38

⇔ x = 38 - 7

⇔ x = 31

Vậy x=31

f) 198 - (x + 4) = 120

⇔ x + 4 = 198 -120

⇔ x + 4 = 78

⇔ x = 78 - 4

⇔ x = 74

Vậy x=74

-38

29

30

104

19

24

a) 71-(33+x) = 76

71-33-x=76

38-x=76

x = -38

các bài cn lại bn lm tương tự nha!
 

71 - ( 33 + x ) = 76

33 + x = -5

x = -38 

Vậy .....

( x + 73 ) - 26 = 76

x + 73 = 102

x = 29

Vậy ....

a) \(\Leftrightarrow-x+38=26\)

\(\Leftrightarrow x=12\)

b)\(\Leftrightarrow x+47=76\)

\(\Leftrightarrow x=29\)

c)\(\Leftrightarrow-x+36=6\)

\(\Leftrightarrow x=30\)

d)\(\Leftrightarrow x+16=20\)

\(\Leftrightarrow x=4\)

e)\(x-18=13\)

\(\Leftrightarrow x=31\)

f)\(-x+194=120\)

\(\Leftrightarrow x=74\)

g)\(\Leftrightarrow x-8=20\)

\(\Leftrightarrow x=28\)

h)\(\Leftrightarrow4x+84=400\)

\(\Leftrightarrow x=79\)

a) 71-(33+x)=26

33+x=71-26

33+x=45

x=45-33

x=12

Vậy x=12

b) ( x+73)-26=76

x+73=76+26

x+73=102

x=102-73

x=29

Vậy x=29

c)45-(x+9)=6

x+9=45-6

x+9=39

x=39-9

x=30

Vậy x=30

d) 89-(73-x)=20

73-x=89-20

73-x=69

x=73-69

x=4

Vậy x=4

e) ( x+7)-25=13

x+7=13+25

x+7=38

x=38-7

x=31

Vậy x=31

f)198-(x+4)=120

x+4=198-120

x+4=78

x=78-4

x=74

Vậy x=74

g)140:(x-8)=7

x-8=140:7

x-8=20

x=20+8

x=28

Vậy x=28

h) 4(x+41)=400

x+41=400:4

x+41=100

x=100-41

x=59

Vậy x=59

Bài 1

a) 71-(33+x)=26

33+x=71-26

33+x=45

x=45-33

x=12

Vậy x=12

b) ( x+73)-26=76

x+73=76+26

x+73=102

x=102-73

x=29

Vậy x=29

c)45-(x+9)=6

x+9=45-6

x+9=39

x=39-9

x=30

Vậy x=30

d) 89-(73-x)=20

73-x=89-20

73-x=69

x=73-69

x=4

Vậy x=4

e) ( x+7)-25=13

x+7=13+25

x+7=38

x=38-7

x=31

Vậy x=31

f)198-(x+4)=120

x+4=198-120

x+4=78

x=78-4

x=74

Vậy x=74

g)140:(x-8)=7

x-8=140:7

x-8=20

x=20+8

x=28

Vậy x=28

h) 4(x+41)=400

x+41=400:4

x+41=100

x=100-41

x=59

Vậy x=59

\(1,\Leftrightarrow7x=42\Leftrightarrow x=6\\ 2,\Leftrightarrow36-4x=4\Leftrightarrow4x=32\Leftrightarrow x=8\\ 3,\Leftrightarrow3x=35\Leftrightarrow x=\dfrac{35}{3}\\ 4,\Leftrightarrow x-12=144\Leftrightarrow x=156\\ 5,\Leftrightarrow x-14=16\Leftrightarrow x=30\\ 6,\Leftrightarrow3x-24=\dfrac{148}{73}\Leftrightarrow3x=\dfrac{1900}{73}\Leftrightarrow x=\dfrac{1900}{219}\\ 7,\Leftrightarrow33+x=45\Leftrightarrow x=12\\ 8,Sai.đề\\ 9,\Leftrightarrow\left(x+9\right):2=39\Leftrightarrow x+9=78\Leftrightarrow x=69\\ 11,\Leftrightarrow2\left(x+7\right)=38\Leftrightarrow x+7=19\Leftrightarrow x=12\\ 13,\Leftrightarrow2\left(x-51\right)=66\Leftrightarrow x-51=33\Leftrightarrow x=84\)

\(15,\Leftrightarrow x-19=9\Leftrightarrow x=28\\ 17,\Leftrightarrow\left(x-3\right):2=48\Leftrightarrow x-3=96\Leftrightarrow x=99\\ 19,\Leftrightarrow0x=46\Leftrightarrow x\in\varnothing\\ 8,Sai.đề\\ 14,\Leftrightarrow2x=209\Leftrightarrow x=\dfrac{209}{2}\\ 16,\Leftrightarrow2x+6=157\Leftrightarrow2x=151\Leftrightarrow x=\dfrac{151}{2}\\ 18,\Leftrightarrow5\left(x+4\right)=100\Leftrightarrow x+4=20\Leftrightarrow x=16\\ 20,\Leftrightarrow\left(3x-5\right)^3=27=3^3\Leftrightarrow3x-5=3\Leftrightarrow x=\dfrac{8}{3}\)

a) 71 - (33 + x) = 26

          33 + x   = 71 - 26

           33 + x  = 45

                  x   = 45 - 33

                  x   = 12

b) (x + 73) - 26 = 76

    (x + 73)       = 76 + 26

    x + 73         = 102

    x                = 102 - 73

    x                = 29

71-(33+x)=26

33+x=71-26

33+x=45

      x=45-33

     x =12

a) 71 - (33 + x) = 26

\(\Rightarrow\)33 + x = 71 - 26 = 45

\(\Rightarrow\)x = 45 - 33 = 12

Vậy giá trị của x là 12

b) (x + 73) - 26 = 76

\(\Rightarrow\)x + 73 = 76 + 26 = 102

\(\Rightarrow\)x = 102 - 73 = 29

Vậy giá trị của x là 29

Ai đúng mình like !

a) \(5x-65=5.3^2 \\ 5x-65=45\\5x=45+65\\5x=110\\x=22\)

b) \(200-(2x+6)=4^3\\2x+6=200-4^3\\2x+6=136\\2x=130\\x=65\)

c) \(2(x-51)=2.2^3+20\\2(x-51)=16+20\\2(x-51)=36\\x-51=18\\x=51+18=69\)

d) \(135-5(x+4)=35\\5(x+4)=135-45\\5(x-4)=90\\x-4=18\\x=18+4=22\)

e) \((2x-4)(15-3x)=0\\2(x-2).3(5-x)=0\\(x-2)(5-x)=0\\ \left[ \begin{array}{l}x-2=0\\5-x=0\end{array} \right. \\ \left[ \begin{array}{l}x=2\\x=5\end{array} \right.\)

f) \(2^{x+1} . 2^{2014}=2^{2016} \\ (2^{x+1} . 2^{2014}):2^{2014}=2^{2016} :2^{2014} \\ 2^{x=1}=2^{2016-2014} \\2^{x+1}=2^2\\x+1=2\\x=1\)

g) \(15+(x-1)^3=43\\(x-1)^3=15-42\\(x-1)^3=-27\\(x-1)^3=(-3)^3\\x-1=-3\\x=-2\)

h) \(15-x=17+(-9)\\15-x=17-9\\15-x=8\\x=15-8\\x=7\)

i) \(|x-5|=|-7|+|-4|\\|x-5|=7+4\\|x-5|=11\\ \left[ \begin{array}{l}x-5=11\\x-5=-11\end{array} \right. \\ \left[ \begin{array}{l}x=16\\x=-6\end{array} \right.\)

k) \(|x-3|-12=-9+|-7|\\|x-3|-12=-9+7\\|x-3|-12=-2\\|x-3|=10 \\ \left[ \begin{array}{l}x-3=10\\x-3=-10\end{array} \right. \\ \left[ \begin{array}{l}x=13\\x=-7\end{array} \right.\)

1, <=>33+x=45
    <=>    x  = 12
Vậy x=12
2, <=>x+73 =102
    <=>   x    =29
3,x=2
4, -23+x=25<=>x=2
6, x-8=20<=>x=28