\(135-5\cdot\left(x+4\right)=35\)

\(5\cdot\left(x+4\right)=135-35\)

\(5\cdot\left(x+4\right)=100\)

\(x+4=100:5\)

\(x+4=20\)

\(x=20-4\)

\(x=16\)

b) \(25+3\cdot\left(x-8\right)=106\)

\(3\cdot\left(x-8\right)=106-25\)

\(3\cdot\left(x-8\right)=81\)

\(x-8=81:3\)

\(x-8=27\)

\(x=27+8\)

\(x=35\)

c) \(3^2\cdot\left(x+4\right)-5^2=5\cdot2^2\)

\(9\cdot\left(x+4\right)-25=5\cdot4\)

\(9\cdot\left(x+4\right)-25=20\)

\(9\cdot\left(x+4\right)=20+25\)

\(9\cdot\left(x+4\right)=45\)

\(x+4=45:9\)

\(x+4=5\)

\(x=5-4\)

\(x=1\)

Chúc bạn học tốt!!!!!!!!!!!!!!!!!!!!

140 : ( x - 8 ) = 7 

          x - 8   = 140 : 7 = 20

               x   = 20 + 8 

               x   = 28

* 140 : (X-8)=7

X-8=140:7

X-8=20

x=20+8

x=28

Vậy X =28

* 4(X+41)=400

X+41=400:4

X+41=100

X=100-41

X=59

Vậy x=59

*135-5(X+4)135

5(X+4)=135-35

5(X+4)=100

X+4=100:5

X+4=20

X=20-4

X=16

Vậy X = 16

a) 135 - 5(x + 4) = 35 

<=> 135 - 5x - 20 = 35

<=> 115 - 5x = 35

<=> 5x = 115 - 35 

<=> 5x = 80 

<=> x = 16

b) 25 + 3 (x - 8) = 106

=>        3 ( x - 8) = 106 - 25

=>        3 ( x - 8) = 81

=>           ( x - 8) = 81: 3

=>             x - 8  = 27

=>             x       = 27 + 8

=>             x       = .......

a)  135-5(x+4)=35

5(x+4)=135-35

5(x+4)=100

x+4=100:5

x+4=20

x=20-4

x=16

b)25+3(x-8)=106

  3(x-8)=106-25

3(x-8)=81

x-8=81:3

x-8=27

x=27+8

x=35

m, 2(x-51)=2.2^3+20

2(x-51)=2.6+20

2(x-51)=32

x-51=32:2

x-51=16

x =16+51

x =67

n, 450:(x-19)=50

x-19 =450:50

x-19 =9

x =9+19

x =28

o, 4(x-3)=7^2-1^10

4(x-3)=49-1

4(x-3)=48

x-3 =48:4

x-3 =12

x =12+3

x =15

p, 135-5(x+4)=35

5(x+4) =135-35

5(x+4) =100

x+4 =100:5

x+4 =20

x =20-4

x =16

q, 25+3(x-8)=106

3(x-8) =106-25

3(x-8) =81

x-8 =81:3

x-8 =27

x =27+8

x =35

r, 3^2(x+4)-5^2=5.2^2

9(x+4)-25=20

9(x+4) =20+25

9(x+4) =45

x+4 = 45:9

x+4 =5

x =5-4

x =1

p, 135 - 5(x+4) = 35

⇒ 5(x+4) = 135 - 35

⇒ 5(x+4) = 100

x + 4 = 100 : 5

x + 4 = 20

x = 20 - 4

x = 16

Vậy : x=16

đề bài là : Tìm x nhé ( vội quá quên đề ahihi)

a: =>x-8=27

hay x=35

a. 25 + 3(x-8) = 106

3(x-8) = 106 - 25 = 81

x -8 = 81 : 3 = 27

x = 27 +8 = 35

b. 3²(x +4) - 5² = 5.5²

9(x+4) - 25 = 5.25 = 125

9(x+4) = 125 + 25 = 150(Đề sai)

3.(x-8) = 106-25

3.(x-8) = 81

x-8 = 81:3

x-8 = 27

x=35

\(a,25+3\left(x-8\right)=106\\ 3\left(x-8\right)=81\\ x-8=27\\ x=35\)

3² . (x + 4 ) - 5² = 5 . 2²

9  . ( x + 4 ) - 25 = 20

9 . ( x + 4 )        = 20 + 25

9 . ( x + 4 )        = 45

     ( x + 4 )       = 45 : 9

      x  + 4          = 5

      x                 = 5 - 4

      x                 = 1

\(a,3\cdot x-15=x+35\)

\(\Rightarrow3x-x=35+15\)

\(\Rightarrow 2x=50\)

\(\Rightarrow x = 50:2\)

\(\Rightarrow x= 25\)

\(b,(8x-16)(x-5)=0\)

\(+, TH1: 8x-16=0\)

\(\Rightarrow8x=16\)

\(\Rightarrow x = 16:8\)

\(\Rightarrow x=2\)

\(+,TH2: x-5=0\)

\(\Rightarrow x =5\)

\(c,x(x+1)=2+4+6+8+10+...+2500\)  \(^{\left(1\right)}\)

Đặt \(A=2+4+6+8+10+...+2500\)

Số các số hạng của \(A\) là: \(\left(2500-2\right):2+1=1250\left(số\right)\)

Tổng \(A\) bằng: \(\left(2500+2\right)\cdot1250:2=1563750\)

Thay \(A=1563750\) vào \(^{\left(1\right)}\), ta được:

\(x\left(x+1\right)=1563750\)

\(\Rightarrow x\left(x+1\right)=1250\cdot1251\)

\(\Rightarrow x =1250\)

#\(Toru\)

Ai biết chỉ mình nha 

1. 11(x-9)=77

x-9=7

x=16

2. 4(x-3)=48

x-3=12

x=15

3.3(x-8)=81

(x-8)=27

x=35

\(40-21:\left(2.x+3\right)=33\)

\(21:\left(2.x+3\right)=40-33\)

\(21:\left(2.x+3\right)=7\)

\(\left(2.x+3\right)=21:7\)

\(\left(2.x+3\right)=3\)

\(2.x=3-3\)

\(2.x=0\)

\(x=0:2\)

\(x=0\)