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

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

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

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

a) \(x=-8\)
b) \(x=-15\)
c) \(x=-30\)

a, 15 + x = 7 

X= 15-7

x= 8

 b, x - 9 = -24 

x= -24+9

x= -15

c, - x + 8 = - 22

-x = -22-8

-x=-30

x=30

a, 15 + x = 7 
X= 7-15
x= -8
 b, x - 9 = -24 
x= -24+9
x= -15
c, - x + 8 = - 22
-x = -22-8
-x=-30
x=30

Phần 1);2) dễ nha nên bạn tự thay vào tính nha nên mk làm phần 3)

C=(a.a+2.a.b+b.b)

C=(a²+2ab +b²)

C=(a.(a+2b)+b²)

Chúc bn học tốt

1) \(\left(x-3\right)^2-4=0\)

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

\(\Leftrightarrow\left(x-5\right)\left(x-1\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x=5\\x=1\end{matrix}\right.\)

2) \(x^2-2x=24\)

\(\Leftrightarrow x^2-2x-24=0\)

\(\Leftrightarrow x^2+4x-6x-24=0\)

\(\Leftrightarrow x\left(x+4\right)-6\left(x+4\right)=0\)

\(\Leftrightarrow\left(x+4\right)\left(x-6\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x=6\\x=-4\end{matrix}\right.\)

Câu 3 số xấu rồi e

alo =0 nhé anh pop pop

ứaedrfgthyjk

a) 2840 + [(999 - 9x) : 60 ] .24 = 3200

=> [(999-9x) : 60 ] . 24 = 2840 - 3200 = -360

=>  (999 - 9x) = \(\frac{-360}{24}=-15\)

=>  9x = 999 - ( - 15) = 999 + 15 = 1014

=>  x = \(\frac{1014}{9}=\frac{338}{3}\)

b) (3x - 48) . 6 = 3³.2² - 2³.3²

(3x - 48) . 6 = 27 . 4  -  8 . 9

(3x -48).6 = 36

(3x - 48 = 36 : 6 = 6

3x = 54

x = 54 : 3 =18

 t ick cho mik nha

1)

a)    2840 + [(999-9x) :60] . 24=3200

                 [(999-9x): 60] . 24=3200- 2840= 360

                (999-9x) : 60=    360 : 24

                (999-9x) : 60= 15

                999-9x        =15 . 60

                  999-9x       =900

                         9x=    999-900=9

                          x=9:9=1

b)   (3x - 48).6=    3³.2²-2³.3²

      (3x-48).6  =   27.4-8.9

       (3x - 48)6  =  108-72

        (3x - 48)6  = 36

       (3x-48)    =   36:6=6

        3x        = 6 + 48

        3x=54

          x=54:3=18

c) \(x^2-9=2\cdot\left(x+3\right)^2\)

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

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

\(\Leftrightarrow\left(x+3\right)\left(x-3-2x-6\right)=0\)

\(\Leftrightarrow\left(x+3\right)\left(-x-9\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x=-3\\x=-9\end{matrix}\right.\)

b) \(x^3-3x^2+3x-1=0\)

\(\Leftrightarrow x^3-3\cdot x^2\cdot1+3\cdot x\cdot1^2-1^3=0\)

\(\Leftrightarrow\left(x-1\right)^3=0\)

\(\Leftrightarrow x-1=0\)

\(\Leftrightarrow x=1\)

d) \(x^2-8x+3x-24=0\)

\(\Leftrightarrow\left(x^2-8x\right)+\left(3x-24\right)=0\)

\(\Leftrightarrow x\left(x-8\right)+3\left(x-8\right)=0\)

\(\Leftrightarrow\left(x+3\right)\left(x-8\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x+3=0\\x-8=0\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}x=-3\\x=8\end{matrix}\right.\)

a) \(x^2-9=2\left(x+3\right)^2\)

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

\(\Leftrightarrow2\left(x+3\right)^2-\left(x+3\right)\left(x-3\right)=0\)

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

\(\Leftrightarrow\left(x+3\right)\left[2x+6-x+3\right]=0\)

\(\Leftrightarrow\left(x+3\right)\left(x+9\right)=0\)

\(\)\(\Leftrightarrow\left[{}\begin{matrix}x+3=0\\x+9=0\end{matrix}\right.\) \(\Leftrightarrow\left[{}\begin{matrix}x=-3\\x=-9\end{matrix}\right.\)

b) \(x^2-8x+3x-24=0\)

\(\Leftrightarrow\left(x-8\right)x+3\left(x-8\right)=0\)

\(\Leftrightarrow\left(x-8\right)\left(x+3\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x-8=0\\x+3=0\end{matrix}\right.\) \(\Leftrightarrow\left[{}\begin{matrix}x=8\\x=-3\end{matrix}\right.\)

c) \(x^3-3x^2+3x-1=0\)

\(\Leftrightarrow\left(x-1\right)^3=0\)

\(\Leftrightarrow x-1=0\)

\(\Leftrightarrow x=1\)

a, (x-15):5+22=24

    ( x - 15 ) : 5 = 2

      x-15  = 10

       x = 25

tớ không biết

 a } 4 / 5 x 3 /y x 2 / 11 = 24 / 165

= 4/5 x 2/11 x 3/y =24/125

=8/55           x 3/y=24/125

= 24/125:8/55

=33/25

4/5 x 3/y x 2/11 = 24/165

3/y x 2/11 = 24/165 : 4/5

3/y x 2/11 = 2/11

3/y = 2/11 : 2/11

3/y = 1 

b. 4/3 : y/5 = 5/13 x 4/9

4/3 : y/5    = 20/117

        y/5    = 4/3 : 20/117

        y/5    = 39/5

=> y = 39

phần a chắc sai nhưng phần b mih chắc chắn

nhớ k mih 3 lần nhé