a: \(\Leftrightarrow x^2\left(9x^2-4\right)=0\)

\(\Leftrightarrow x^2\left(3x-2\right)\left(3x+2\right)=0\)

hay \(x\in\left\{0;\dfrac{2}{3};-\dfrac{2}{3}\right\}\)

b: \(\Leftrightarrow2x^4-4x^2+3x^2-6=0\)

\(\Leftrightarrow x^2-2=0\)

hay \(x\in\left\{\sqrt{2};-\sqrt{2}\right\}\)

d: \(\Leftrightarrow x^4-9x^2+6x^2-54=0\)

\(\Leftrightarrow x^2-9=0\)

=>x=3 hoặc x=-3

18 - 4\(x\) = -20 - 6\(x\) 

-4\(x\) + 6\(x\) = - 20  - 18

      2\(x\)    = - 38

         \(x\)  = - 19

h, -15 \(\times\) 24 = -7\(x\) + 32

     7\(x\) = 360 + 32

      7\(x\) = 392

         \(x\) =  392:7

          \(x\) = 56

i, 15\(x\) -3.(4\(x\) - 6) = -12 + 36

    15\(x\) - 12\(x\) + 18 =  24

      3\(x\) = 24 - 18

       3\(x\) = 6

         \(x\) = 2

k, -10\(x\) - 27 = -7\(x\) + 33

    -27 - 33 = -7\(x\) + 10\(x\)

     3\(x\) = -60

        \(x\) = -20

m, -17\(x\) - 24 = - 9\(x\) - 40

     - 24 + 40 =  -9\(x\) + 17\(x\)

          8\(x\) = 16

             \(x\) = 2

n, -23 \(\times\) 25 = -18\(x\) + 75

     -575 = -18\(x\) + 75

       18\(x\) = 575 + 75

        18\(x\) = 650

              \(x\) = \(\dfrac{325}{9}\)

a: Ta có: \(\sqrt{9x-54}-\sqrt{4x-24}=2\)

\(\Leftrightarrow3\sqrt{x-6}-2\sqrt{x-6}=2\)

\(\Leftrightarrow x-6=4\)

hay x=10

b: Ta có: \(\sqrt{4x^2+4x+1}=7\)

\(\Leftrightarrow\left|2x+1\right|=7\)

\(\Leftrightarrow\left[{}\begin{matrix}2x+1=7\\2x+1=-7\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}2x=6\\2x=-8\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=3\\x=-4\end{matrix}\right.\)

18x -19 = 21 + 8x 

18 x - 8x = 21 + 19 

10 x = 40

x =4 

g) 18 -4x=-20-6x

-4x + 6x = -20 - 18

2x = -38

x= -19

k, -10 \(x\) - 27 = -7\(x\) + 33

   -27 - 33 = -7\(x\) + 10\(x\)

3\(x\)             = -60

   \(x\)            - 20

m, -17\(x\) - 24 = -9\(x\) - 40

     -24 + 40 = -9\(x\) + 17\(x\)

     8\(x\)          = 16

       \(x\)           = 2

h)-15x -24 = 7x + 32 

-15x - 7x = 32 + 24 

-22x = 56 

x = \(-\dfrac{14}{5}\)

i)15x -3(4x -6)=-12+36

15x - 12x + 18 = 24

3x + 18 = 24 

3x = 24 - 18

3x = 6 

x=2

\(\dfrac{1}{9x-18}+\dfrac{16-7x}{72-18x}+\dfrac{5}{12x+24}\)

=\(\dfrac{\left(72-18x\right)\left(12x+24\right)}{\left(9x-18\right)\left(72-18x\right)\left(12x+24\right)}+\dfrac{\left(16-7x\right)\left(9x-18\right)\left(12x+24\right)}{\left(72-18x\right)\left(9x-18\right)\left(12x+24\right)}+\dfrac{5\left(9x-18\right)\left(72-18x\right)}{\left(12x+24\right)\left(9x-18\right)\left(72-18x\right)}\)

=\(\dfrac{\left(72-18x\right)\left(12x+24\right)+\left(16-7x\right)\left(9x-18\right)\left(12x+24\right)+5\left(9x-18\right)\left(72-18x\right)}{\left(9x-18\right)\left(72-18x\right)\left(12x+24\right)}\)

=\(\dfrac{-756x^3+702x^2+8316x-11664}{\left(9x-18\right)\left(72-18x\right)\left(12x+24\right)}\)

=

Ngô thừa ân cái đề nhìn rối quá bạn ơi , có thể viết rõ ra hơn được không !

mik ko thể ghi đươc vì nó ko cho ghi

e, \(18x-19=21+8x\)

\(\Rightarrow18x-8x=21+19\)

\(\Rightarrow10x=30\)

\(\Rightarrow x=3\)

Vậy \(x=3\)

g, \(18-4x=-20-6x\)

\(\Rightarrow-4x+6x=-20-18\)

\(\Rightarrow-2x=-38\)

\(\Rightarrow x=19\)

Vậy \(x=19\)

h, \(-15x-24=-7x-32\)

\(\Rightarrow-15x+7x=-32+24\)

\(\Rightarrow-8x=-8\)

\(\Rightarrow x=1\)

Vậy \(x=1\)

i, \(15x-3\left(4x-6\right)=-12+36\)

\(\Rightarrow15x-12x+18=-12+36\)

\(\Rightarrow7x=-12+36-18\)

\(\Rightarrow7x=6\)

\(\Rightarrow x=\frac{6}{7}\)

Vậy \(x=\frac{6}{7}\)

k, \(-10x-27=-7x+33\)

\(\Rightarrow-10x+7x=33+27\)

\(\Rightarrow-3x=60\)

\(\Rightarrow x=-20\)

m, \(-17x-24=-9x-40\)

\(\Rightarrow-17x+9x=-40+24\)

\(\Rightarrow-8x=-16\)

\(\Rightarrow x=2\)

Vậy \(x=2\)

n, \(-23x-25=-18x+75\)

\(\Rightarrow-23x+18x=75+25\)

\(\Rightarrow-5x=100\)

\(\Rightarrow x=-20\)

Vậy \(x=-20\)

p, \(-5x+7\left(2x-3\right)=4\left(x-4\right)\)

\(\Rightarrow-5x+14x-21=4x-16\)

\(\Rightarrow-5x+14x-4x=-16+21\)

\(\Rightarrow5x=5\)

\(\Rightarrow x=1\)

Vậy \(x=1\)

q, \(24-6\left(3x+1\right)=-5\left(4x-4\right)-8\)

\(\Rightarrow24-18x-6=-20x+20-8\)

\(\Rightarrow-18x+20x=20-8-24+6\)

\(\Rightarrow2x=-6\)

\(\Rightarrow x=-3\)

Vậy \(x=-3\)

r, \(18-4\left(6-2x\right)=-3\left(4x+5\right)-11\)

\(\Rightarrow18-24+8x=-12x-15-11\)

\(\Rightarrow8x+12x=-15-11-18+24\)

\(\Rightarrow20x=-20\)

\(\Rightarrow x=-1\)

Vậy \(x=-1\)

s, \(-5\left(4x-5\right)-14=6\left(2-3x\right)-10x-9\)

\(\Rightarrow-20x+25-14=12-18x-10x-9\)

\(\Rightarrow-20x+18x+10x=12-9+14-25\)

\(\Rightarrow8x=-8\)

\(\Rightarrow x=-1\)

Vậy \(x=-1\)

Chúc bạn hok tốt!!! tỷ tỷ

\(4x^3-13x^2+9x-18=4x^3-12x^2-x^2+3x+6x-18\)

\(=4x^2.\left(x-3\right)-x\left(x-3\right)+3.\left(x-3\right)=\left(x-3\right)\left(4x^2-x+3\right)\)

\(4x^3-13x^2+9x-18\)

\(=4x^3-12x^2-x^2+3x+6x-18\)

\(=4x^2\left(x-3\right)-x\left(x-3\right)+6\left(x-3\right)\)

\(=\left(x-3\right)\left(4x^2-x+6\right)\)