mong các bn giúp mik, mik đag cần gấp 

-2x+3{12-2[3x-20-2x-4x]+1}=45

-2x+3[12-2(-3x-20)+1]=45

-2x+3(12+6x+40+1)=45

16x+159=45

16x=-114

x=-7,125

\(\Leftrightarrow-2x+3\cdot\left\{12-2\left[3x-20-2x-4x\right]+1\right\}=45\)

\(\Leftrightarrow-2x+3\cdot\left\{12-2\cdot\left(-3x-20\right)+1\right\}=45\)

=>-2x+3(11+6x+40)=45

=>-2x+153+18x=45

=>16x=45-153=-108

hay x=-6,75

Ta có :-2x + 3x . { 12-2.[ 3.x-(20+2.x) - 4.x ] + 1 } = 45

<=>-2.x +3.x. [ 12-2 .( 3.x - 20 - 2.x  - 4.x )+1 ) = 45

<=> -2.x + 3.x . [ 12- 2 ( -3.x -20 ) + 1 ] = 45

<=> -2.x + 3.x . ( 12 + 6.x + 40 + 1 )  = 45

<=>-2.x + 3.x . ( 53 + 6.x ) = 45

<=> -2.x + 159.x + 18.x² = 45

<=> 157 .x + 18.x² = 45

<=> 157.x + 18.x² - 45 = 0

<=> 18.x² - 5.x + 162.x - 45 = 0

<=> x. ( 18.x-5 ) + 9 .( 18.x-5) = 0

<=> ( 18.x-5 ) . ( x + 9 ) = 0

<=> \(\orbr{\begin{cases}18.x-5=0\\x+9=0\end{cases}}\)

<=> \(\orbr{\begin{cases}x=\frac{5}{18}\\x=-9\end{cases}}\)

Vậy x = { \(\frac{5}{18};-9\)}

giúp mk

\(-2x+3.\left\{12-2.\left[3x-\left(20+2x\right)-4x+1\right]\right\}=45\)

\(\Leftrightarrow-2x+3.\left\{12-2\left[3x-20-2x-4x+1\right]\right\}=45\)

\(\Leftrightarrow-2x+3.\left\{12-2.\left[-3x-19\right]\right\}=45\)

\(\Leftrightarrow-2x+3.\left\{12+6x+38\right\}=45\)

\(\Leftrightarrow-2x+36+18x+114=45\)

\(\Leftrightarrow16x+150=45\Leftrightarrow16x=-105\Leftrightarrow x=\frac{-105}{16}\)

mình giúp rùi đó nhớ k mk nhé ....

= -2x + 3[12-2(3x-20-2x-4x+1)]=45

= -2x +3[12-2(-3x-19)]=45

= -2x+3(12+6x+38)=45

= -2x+3(6x+50)=45

=-2x+18x+150=45

=16x=-105

=>x=-105/16