a ) 2x - 138 = 2 ^ 3 . 3 ^ 2

     2x - 138 = 8 . 9

     2x - 138 = 72

     2x          = 210

       x          = 105

b ) ( 3x - 2 ^ 4 ) . 7 ^ 2 = 2 . 7 ^ 4

     ( 3x - 16 ) . 49         = 4802

     ( 3x - 16 )                = 98

       3x                         = 114

         x                         = 38

a) \(12.4+225:\left(x-3\right)^2=37\)

\(48+225:\left(x^2-6x+9\right)=37\)

\(48+\frac{225}{x^2}-\frac{225}{6x}+\frac{225}{9}=37\)

\(48+\frac{15}{x}-\frac{37,5}{x}+25=37\)

\(48-\frac{22,5}{x}+25=37\)

\(\frac{-22,5}{x}=37-25-48\)

\(\frac{-22,5}{x}=-36\)

\(x=-22,5:-36\)

\(x=\frac{5}{8}\)

vậy \(x=\frac{5}{8}\)

b) \(2x-138=2^3.3^2\)

\(2x-138=72\)

\(2x=72+138\)

\(2x=210\)

\(x=105\)

vậy \(x=105\)

b,2 nhân x - 138 =72

2 nhân x =72 + 138

2 nhân x =210

x =210 : 2

x =105

a)\(2.x-138=8.9\)

\(2.x-138=72\)

\(2.x=72+138\)

\(2.x=210\)

\(x=210\div2\)

\(x=105\)

b)\(\left\{\left(6x-72\right)\div2-84\right\}.28=5628\)

\(\left(6x-72\right)\div2-84=201\)

\(\left(6x-72\right)\div2=285\)

\(6x-72=570\)

\(6x=642\)

\(x=107\)

c)\(420+65.4=\left(x+175\right)\div5+30\)

\(420+260=\left(x+175\right)\div5+30\)

\(680=\left(x+175\right)\div5+30\)

\(650=\left(x+175\right)\div5\)

\(3250=x+175\)

\(3075=x\)

a) 2 * x - 138 = 72

    2 * x          = 72 + 138

    x                = 210 \ 2

    x                = 105

Mk thay x=y nha!!!

a)2xy-138=8x9

2xy-138=72

2xy=72+138

2xy=210

y=210:2

y=105

b){(6xy-72):2-84)}x28=5628

{(6xy-72):2-84)}x28=5628

{(6xy-72):2-84=201

{(6xy-72):2=285

(6xy-72)=570

6y=570+72

6y=642

=>y=107

c)420+65x4=(y+175):5+30

680=(y+175):5+30

650=(y+175):5

3250=y+175

y=3250-175

y=3075

a, 210

 b, ko hiểu

a)   2x - 138 = x + 2³ * 3² 

     2x - 138 = x + 17

     2x = x + 17 + 138 

     2x - x = 17 + 138 = 155

     x    =          155

b)    De sai a ?

2.x – 138 = 23.32

2x – 138 = 8.9

2x – 138 = 72

2x = 72 + 138

2x = 210

x = 210 : 2

x = 105

Vậy x = 105

a) 70 - 5 (x - 3) = 45

 5 (x - 3) =70-45

 5 (x - 3) =25

 (x - 3)=25:5

 (x - 3)=5

x=5+3

x=8

b) 10 + 2.x = 4^5 : 4^3

10 + 2.x=4^2

10 + 2.x=16

2.x=16-10

2.x=6

x=6:2

x=3

c) 2x - 138 = 2^3 . 3^2

2x - 138 = 8.9

2x - 138 = 72

2x=72+138

2x=210

x=210:2

x=105

d) 231 - (x - 6) = 133 : 13

 (đề sai)

x=246*5+4

x=1230+4

x=1234

Do x là một số chẵn và xchia cho 5 được 246 dư 4

\(\Rightarrow\)x=5x246+4

\(\Rightarrow\)x=1230+4

\(\Rightarrow\)x=1234

Do x-(246+4)²=-967022

Mà (246+4)²=62500

\(\Rightarrow\)x-(246+4)² \(\ne\)-967022

\(\Rightarrow\)đề sai

Sao ko có ai trả lời được vậy