= \(\dfrac{2x^3+5-x^3-4}{x^2-x+1}\) = \(\dfrac{x^3-1}{x^2-x+1}\)

\(\dfrac{2x^3+5 -x^3-4}{x^2-x+1}=\dfrac{x^3+1 }{x+1}\)

câu này luôn \(\dfrac{2x^2y^5}{xy^2z}-\dfrac{4x^2y^3}{xy^2z}\)

`#3107.\text {DN}`

\(3^{x+2}+4\cdot3^{x+1}+3^{x-1}=6^6\)

`=> 3^x*3^2 + 4*3^x*3 + 3^x * 1/3 = 6^6`

`=>3^x*(3^2 + 12 + 1/3) = 6^6`

`=> 3^x * 64/3 = 6^6`

`=> 3^x = 6^6 \div 64/3`

`=> 3^x = 2187`

`=> 3^x = 3^7`

`=> x = 7`

Vậy, `x = 7.`

​a: \(A=\dfrac{2\sqrt{x}-2+2\sqrt{x}+x-3\sqrt{x}}{\left(\sqrt{x}-1\right)\left(\sqrt{x}-3\right)}\)

\(=\dfrac{x+\sqrt{x}-2}{\left(\sqrt{x}-1\right)\left(\sqrt{x}-3\right)}=\dfrac{\sqrt{x}+2}{\sqrt{x}-3}\)

b: Để A=2 thì căn x+2=2 căn x-6

=>-căn x=-8

=>x=64

\((6x+1)^2-2(x+1)^3+2(x-1)(x^2+x+1)=1\)

\(\Leftrightarrow36x^2+12x+1-2\left(x^3+3x^2+3x+1\right)+2\left(x^3-1\right)=1\)

\(\Leftrightarrow36x^2+12x+1-2x^3-6x^2-6x-2+2x^3-2=1\)

\(\Leftrightarrow30x^2+6x-4=0\)\(\Leftrightarrow2\left(15x^2+3x-2\right)=0\)

\(\Leftrightarrow15x^2+3x-2=0\)\(\Leftrightarrow15\left(x+\dfrac{1}{10}\right)^2-\dfrac{43}{20}=0\)

\(\Leftrightarrow15\left(x+\dfrac{1}{10}\right)^2=\dfrac{43}{20}\Leftrightarrow x=\pm\dfrac{\sqrt{129}}{30}-\dfrac{1}{10}\)

1/2.x+3/5.x-3/5.2=3

=>11/10.x=3+6/5

=>11/10.x=21/5

=>x=42/11

\(\dfrac{1}{5}\times x-\dfrac{2}{3}=\dfrac{1}{10}\times x+\dfrac{5}{6}\)

\(\dfrac{1}{5}x-\dfrac{2}{3}-\dfrac{1}{10}x-\dfrac{5}{6}=0\)

\(\dfrac{1}{5}x-\dfrac{1}{10}x-\dfrac{2}{3}-\dfrac{5}{6}=0\)

\(\dfrac{1}{10}x-\dfrac{3}{2}=0\)

\(\dfrac{1}{10}x=\dfrac{3}{2}\)

\(x=15\)

           \(\dfrac{1}{5}\).x - \(\dfrac{2}{3}\) = \(\dfrac{1}{10}\).x + \(\dfrac{5}{6}\)

⇒   \(\dfrac{1}{5}\).x - \(\dfrac{1}{10}\).x = \(\dfrac{5}{6}\) + \(\dfrac{2}{3}\)

⇒ \(\dfrac{2}{10}\).x - \(\dfrac{1}{10}\).x = \(\dfrac{5}{6}\) + \(\dfrac{4}{6}\)

⇒            \(\dfrac{1}{10}\).x = \(\dfrac{9}{6}\)

⇒                  x = \(\dfrac{9}{6}\) : \(\dfrac{1}{10}\)

⇒                  x = \(\dfrac{9}{6}\) . 10

⇒                  x = \(\dfrac{90}{6}\)

⇒                  x = 15

       Vậy x = 15

24 - 16(x - 1/2) = 23

=> 16(x - 1/2) = 24 - 23

=> 16(x - 1/2) = 1

=> x - 1/2 = 1/16

=> x = 1/16 + 1/2

=> x = 9/16

\(24-16(x-\frac{1}{2})=23\)

\(16(x-\frac{1}{2})=24-23\)

\(16(x-\frac{1}{2})=1\)

\(x-\frac{1}{2}=\frac{1}{16}\)

\(x=\frac{1}{16}+\frac{1}{2}\)

\(x=\frac{9}{16}\)

Vậy số thực x cần tìm là \(\frac{9}{16}\)

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