giao cho mik

a)346.124 - 7.(2x - 1 ) = 346

      42904 - 7.(2x - 1 ) = 346

                  7.(2x - 1 ) = 42904 - 346

                  7.(2x - 1 ) = 42558

                        2x - 1 = 42558 :7

                        2x - 1 = 42558/7

                             2x = 42558/7+1 

                             2x = 42565/7

                               x = 42565/7:2

                               x = 42565/14

a)346.124 - 7.(2x - 1 ) = 346

      42904 - 7.(2x - 1 ) = 346

                  7.(2x - 1 ) = 42904 - 346

                  7.(2x - 1 ) = 42558

                        2x - 1 = 42558 :7

                        2x - 1 = 42558/7

                             2x = 42558/7+1 

                             2x = 42565/7

                               x = 42565/7:2

                               x = 42565/14

346.124-7.(2x-1)=346

Suy ra: 7.(2x-1)=346.123-346

Nên: 7.(2x-1)=346.(123-1)

7.(2x-1)=346.122

2x-1=42212:7

2x-1=42212 phần 7

2x=42212 phần 7+1

2x=42219 phần 7

x=42219 phần 7:2

Vậy x=42219 phần 14

4 phần 3+2.(5+7x)=115:5

4 phần 3+2.(5+7x)=23

2.(5+7x)=23:4 phần 3

2.(5+7x)=69 phần 4

5+7x=69 phần 4:2

5+7x=69 phần 8

7x=69 phần 8 -5

7x=29 phần 8

x=29 phần 8:7

Vậy x=29 phần 56

a) 7(2x-1)=(346.124)-346

14x-7=42558

14x=42551

x=42551/14

b) 4/3+2(5+7x)=23

2(5+7x)=65/3

5+7x=65/6

7x=35/6

x=5/6

a) 346.124-7.(2x-1)=343

346.124-14x+7=343

42904-14x+7=343

-14x=343-42904-7

-14x=-42568

x=\(\dfrac{-42568}{-14}\)=\(\dfrac{42568}{14}\)=3,04

vậy x = 3,04

b)\(\dfrac{4}{3}\)+2(5+7x)=115:5

\(\dfrac{4}{3}\)+10+14x=23

14x=23-10-\(\dfrac{4}{3}\)

14x= \(\dfrac{35}{3}\)

x=\(\dfrac{35}{3}\):14

x=\(\dfrac{35}{42}\)=\(\dfrac{5}{6}\)

a:\(\Leftrightarrow7\left(2x-1\right)=346\cdot124-346=42558\)

=>2x-1=42558/7

=>2x=42565/7

hay x=42565/14

b: \(\Leftrightarrow2\left(7x+5\right)=23-\dfrac{4}{3}=\dfrac{65}{3}\)

=>7x+5=65/6

=>7x=35/6

hay x=5/6

a) ( 2x - 3 ) - ( x - 5 ) = ( x + 7 ) - ( x + 2 ) 

<=> 2x - 3 - x + 5 = x + 7 - x - 2

<=> x = 3

b)(7x-5)-(6x+4)=(2x+3)-(2x+1)

<=> 7x - 5 - 6x - 4 = 2x + 3 - 2x - 1

<=> x = 11

c)(9x-3)-(8x+5)=(3x+2)

<=> 9x - 3 - 8x - 5 = 3x + 2

<=> -2x = 10

<=> x = -5

d)(x+7)-(2x+3)=(3x+5)-(2x+4)

<=> x + 7 - 2x - 3 = 3x + 5 - 2x - 4

<=> -2x = -3

<=> x = 3/2

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Mài ngu

a) 5(2x -1) - 4(8 - 3x) = 7

<=> 10x - 5 - 32 + 12x = 7

<=> 22x = 44 

<=> x =2

Vậy x = 2 là nghiệm phương trình

b) 7(2x - 5) - 5(7x - 2) + 2(5x - 7) = (x - 2) - (x + 4) 

<=> 14x - 35 - 35x + 10 + 10x - 14 = x - 2 - x - 4

<=> -11x - 39 = - 6

<=> -11x = 33

<=> x = -3

Vậy x = -3 là nghiệm phương trình 

\(a,10x-5-32+12x=7\)

\(22x=44\)

\(x=2\)

\(b,14x-35-35x+10+10x-14=x-2-x-4\)

\(-11x-39=-6\)

\(-11x=-33\)

\(x=3\)

sửa lại đoạn cuối

\(-11x=33\)

\(x=-3\)

a) 2x-5=3+2x-7x

2x-2x+7x=3+5

7x=8

  x=8/7

vậy x=8/7

a) 2x - 5 = 3 + 2x - 7x

=> 2x - 2x + 7x = 3 +5 

=> 7x = 8

=> x = 8/7

b) \(\left(2x-1\right)^2=\left(2x-1\right)^5\)

=> \(\left(2x-1\right)^2-\left(2x-1\right)^5=0\)

=> \(\left(2x-1\right)^2\left[1-\left(2x-1\right)^3\right]=0\)

=> \(\orbr{\begin{cases}\left(2x-1\right)^2=0\\1-\left(2x-1\right)^3=0\end{cases}}\)

=> \(\orbr{\begin{cases}2x-1=0\\\left(2x-1\right)^3=1\end{cases}}\)

=> \(\orbr{\begin{cases}2x=1\\2x-1=1\end{cases}}\)

=> \(\orbr{\begin{cases}x=\frac{1}{2}\\2x=2\end{cases}}\)

=> \(\orbr{\begin{cases}x=\frac{1}{2}\\x=1\end{cases}}\)

\(1,\\ a,=7x^3-49x^2+21x\\ b,=x^2-x-42\\ c,=x^2-16x+64\\ d,=9x^2+12x+4\\ e,=x^2-16-25+10x-x^2=10x-41\\ 2,\\ a,\Rightarrow2\left(x-7\right)=19\\ \Rightarrow x-7=\dfrac{19}{2}\Rightarrow x=\dfrac{33}{2}\\ b,\Rightarrow4x^2-20x+25-4x^2+3x-2x=50\\ \Rightarrow-19x=25\Rightarrow x=-\dfrac{25}{19}\)

a ) \(-5\times\left(-x+7\right)-3\times\left(-x-5\right)=-4\times\left(12-x\right)+48\)

\(\Leftrightarrow5x-35+3x+15=-48+4x+48\)

\(\Leftrightarrow5x-3x+4x=35-15-48+48\)

\(\Leftrightarrow2x=20\)

\(\Leftrightarrow x=10\)

b ) \(-2\times\left(15-3x\right)-4\times\left(-7x+8\right)=-5-9\times\left(-2x+1\right)\)

\(\Leftrightarrow-30+6x-28x-32=-5+18x-9\)

\(\Leftrightarrow6x-28x-18x=30+32-5-9\)

\(\Leftrightarrow-40x=48\)

\(\Leftrightarrow x=-1.2\)

C,D nưã bạn

 c, 7 . ( - x - 7 ) - 5 . ( - x - 3 ) = 12 . ( 3 - x)

<=> - 7x - 49  + 5x  + 15 = 36 - 12x

<=>  - 2x + 12x = 36 - 15 + 49

<=> 10 x = 70

<=> x = 7

Vẫy  x = 7

d, 5 . ( - 3x - 7 ) - 4 . ( - 2x - 11 ) = 7 . ( 4x + 10) + 9

<=> - 15x + 8x + 44 = 28x + 70 + 9

<=> - 7x + 44 = 28x + 79

<=> - 7x - 28x = 79 - 44

<=> - 35x = 35

<=> x = - 1

Vậy x = - 1

Hc tốt