a) x=5

b) x=3

c) x=2

d) x=7

+5

a.(3^2+4^2).x=10^2

(9+16).x     =100

25.x           =100

x                =100:25

x                =4

b.(x-5)^2       =81

x-5             =9

x                =9+5

x                =14

c.(2x+1)^3 = 343

2x+1          = 7

2x              =7-1

2x              =6

x                =6:2

x                = 3

(9+16).x=100

25.x=100

x=100:25

x=4

bích ngọc sai rồi nhé

Rút gọn hả bạn ?

( 3x - 1 )² - 9( x - 1 )( x + 1 )

= 9x² - 6x + 1 - 9( x² - 1 )

= 9x² - 6x + 1 - 9x² + 9

= 10 - 6x

( 2x + 3 )( 2x - 3 ) - ( 2x - 1 )² - ( x - 1 )

= 4x² - 9 - ( 4x² - 4x + 1 ) - x + 1

= 4x² - x - 8 - 4x² + 4x - 1

= 3x - 9

2( x - 2y )( x + 2y ) + ( x - 2y )² + ( x + 2y )²

= [ ( x + 2y ) + ( x - 2y ) ]²

= [ x + 2y + x - 2y ]²

= ( 2x )² = 4x²

1) \(\Rightarrow x^2\left(x^{2004}-1\right)=0\)

\(\Rightarrow\left[{}\begin{matrix}x=0\\x^{2004}=1\end{matrix}\right.\)\(\Rightarrow\left[{}\begin{matrix}x=0\\x=1\\x=-1\end{matrix}\right.\)

2) \(\Rightarrow\left(x-5\right)^4\left[\left(x-5\right)^2-1\right]=0\)

\(\Rightarrow\left[{}\begin{matrix}x-5=0\\\left(x-5\right)^2=1\end{matrix}\right.\)\(\Rightarrow\left[{}\begin{matrix}x=5\\x-5=1\\x-5=-1\end{matrix}\right.\)\(\Rightarrow\left[{}\begin{matrix}x=5\\x=6\\x=4\end{matrix}\right.\)

a, \(\left(x+\frac{4}{3}y^2\right)^2\)

\(=x^2+\frac{8}{3}xy^2+\frac{16}{9}y^4\)

b, \(\left(2x-3y\right)^2\)

\(=4x^2-12xy+9y^2\)

c, \(\left(x^2+2x\right)\left(2x-x^2\right)\)

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

\(=4x^2-x^4\)

d, \(\left(x+\frac{1}{2}\right)^3\)

\(=x^3+\frac{3}{2}x^2+\frac{3}{4}x+\frac{1}{8}\)

e, \(\left(2x-\frac{6}{5}y\right)^3\)

\(=8x^3-\frac{72}{5}x^2y+\frac{216}{25}xy^2-\frac{216}{125}y^3\)