( 4/9 + 7/9 -  2/9 ) x 19/24  = 1 x 19/24 = 19/24

\(=\dfrac{19}{24}\times\left(\dfrac{4}{9}+\dfrac{7}{9}-\dfrac{2}{9}\right)=\dfrac{19}{24}\times1=\dfrac{19}{24}\)

\(\dfrac{19}{24}\times\left(\dfrac{4}{9}+\dfrac{7}{9}-\dfrac{2}{9}\right)\)

\(=\dfrac{19}{24}\times1=\dfrac{19}{24}\)

1, 24:x=24:2

x=24x2:24=2

a) 24:x=24:2

⇒ x=2

b) 9:x>9:2

⇒ x<2

a) 24:x=24:2

24:x=12

x=24:12

x=2

b)9:x>9:2

\(\dfrac{9}{x}>\dfrac{9}{2}\Rightarrow x=1\)

1) 10/2/5 hay 52/5
2) 90

a)\(\dfrac{x}{60}=-\dfrac{3}{4}\)

\(\Rightarrow x\cdot4=60\cdot\left(-3\right)\)

   \(x\cdot4=-180\)

  x=45

b)\(\dfrac{2}{5}=\dfrac{12}{x}\)

   \(\Rightarrow2x=5\cdot12\)

      \(2x=60\)

       x=30

c)\(x-\dfrac{5}{7}=\dfrac{6}{21}\)

      \(x=\dfrac{2}{7}+\dfrac{5}{7}\)

      x=1

d)\(x+\dfrac{7}{8}=\dfrac{63}{24}\)

     \(x=\dfrac{21}{8}-\dfrac{7}{8}\)

     \(\dfrac{14}{8}\)

a)\(\dfrac{x}{60}=\dfrac{-3}{4}\Rightarrow x=\dfrac{-3.60}{4}=-45\)

b)\(\dfrac{2}{5}=\dfrac{12}{x}\Rightarrow x=\dfrac{5.12}{2}=30\)

1)   \(152\times9+152\times1=152\times\left(9+1\right)=152\times10=1520\)

2)    \(24\times999+24\times1=24\times\left(999+1\right)=24\times1000=24000\)

1/ 152 x 9 + 152 x 1 = 152 x ( 9 + 1 ) = 152 x 10 = 1520

2/ 24 x 999 + 24 x 1 = 24 x ( 999 + 1 ) = 24 x 1000 = 24000

`9 -(x-3)^2 -24(x-3) = 0`

`<=> (x-3) (9-24-x+3)=0`

`<=> (x-3) ( -12-x)=0`

\(\Leftrightarrow\left[{}\begin{matrix}x-3=0\\-12-x=0\end{matrix}\right.\\ \Leftrightarrow\left[{}\begin{matrix}x=3\\x=-12\end{matrix}\right.\)

dmm

a: \(\left(x+1\right)^3+\left(x-2\right)^3=2x^3+2\left(2x-1\right)^2-9\)

\(\Leftrightarrow x^3+3x^2+3x+1+x^3-6x^2+12x-8=2x^3+2\left(4x^2-4x+1\right)-9\)

\(\Leftrightarrow2x^3-3x^2+15x-7=2x^3+8x^2-8x-7\)

\(\Leftrightarrow-11x^2+23x=0\)

\(\Leftrightarrow x\left(-11x+23\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x=0\\x=\dfrac{23}{11}\end{matrix}\right.\)