x=103/23

-[-3x+2(45-x-9x+21-2x)+4x=55       

-[-3x+2(24-12x)+4x]=55

-(-3x+48-24x+4x)=55

-(48-23x)=55

23x=55+48

x=103/23

Xem lại dùm mink nha

mong các bn giúp mik, mik đag cần gấp 

\(\left\{-3x+2\left[45-x-3\left(3x+7\right)-2x\right]+4x\right\}=55-103\)

\(\left\{-3x+2\left[45-x-9x-21-2x\right]+4x\right\}=-48\)

\(-3x+90-2x-18x-42-4x+4x=-48\)

\(-3x-2x-18x-4x+4x=-48-90+42\)

\(-23x=-96\Leftrightarrow x=\frac{96}{23}\)

đag rảnh nên ... lm nốt 

\(-57:\left[-2\left(2x+1\right)^2-\left(-9\right)^0\right]=-106\)

\(-2\left(2x+1\right)^2+1=57\)

\(-2\left(2x+1\right)^2=56\)

\(\left(2x+1\right)^2=-28\)

\(\Rightarrow\orbr{\begin{cases}2x+1=-2\sqrt{7}\\2x+1=2\sqrt{7}\end{cases}\Rightarrow\orbr{\begin{cases}2x=-1-2\sqrt{7}\\2x=-1+2\sqrt{7}\end{cases}}}\)

\(\Rightarrow\orbr{\begin{cases}x=\frac{-1-2\sqrt{7}}{2}\\x=\frac{-1+2\sqrt{7}}{2}\end{cases}}\)

a,-2x -(x-17)=34-(-x+25)

-2x-x+17=34+x-25

-3x+17=9+x

-3x-x=9-17

-4x=-8

-->4x=8

x=8:4

x=2

Vậy x=2

b,17-(16x-37)=2x+43

17-16x+37=2x+43

20-16x=2x+43

-16x-2x=43-20

-18x=23

x=23:(-18)

x=23/-18

Mà x là số nguyên nên --> x thuộc tập rỗng

c,-2x-3.(x-17)=34-2(-x+25)

-2x-3x+51=34-2.(-x)-25

-5x+51=9-(-2).x

-5x+(-2).x=9-51

-7x=-42

7x=42

x=42:7

x=6

Vậy x=6

3x+2{45-x-3[3x+7]-2x}+4x=55

<=>3x+2[45-x-9x-27-2x]+4x=55

<=>3x+90-2x-18x-54-4x+4x=55

<=>36-17x=55

<=>17x=-19

<=>x=-19/17

Vậy x=-19/17

3x+2{45-x-3[3x+7]-2x}+4x=55

=> 7x+2{45-x-9x-21-2x}=55

=>7x+2{24-12x}=55

=>7x+48-24x=55

=>-17x=7

=> x=\(\frac{-7}{17}\)

3x + 2{45-x-9x -21 - 2x } + 4x = 55

suy ra 3x + 2{24-12x}+4x=55

suy ra 3x + 48 - 24x + 4x = 55

suy ra 17x=-7

suy ra x=-7/17

ko chép lại đề bài

<=> {(-3x+4x)+2[ 45-(x+2x)-9x-21]}=55

<=> {x+2[(45-21)-(3x+9x)]}=55

<=> x+2[24-12x]=55

<=> x+48-24x=55

<=> 48-23x=55

<=>23x=48-55=-7

<=>x=\(\frac{-7}{23}\)