(x + 2)(x - 2) - (x - 2)(x + 5)

= (x - 2)(x + 2 - x - 5)

= (x - 2)-3

= -3x + 6

b) 2x(3x²y + 4x²y - 3)

= 2x(7x²y - 3)

= 14x³y - 6x

bạn giải hết đc ko ạ

a) (x+2)(x-2) - (x-2)(x+5 )

= (x-2) (x+2 - x-5)

= -3 (x-2)

c) \(\left(3x+1\right)^2\) - \(\left(1-2x\right)^2\)

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

= 5x (x +2)

d) \(x^2\) - 4 - \(\left(x+2\right)^2\)

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

= (x-2) (x+2) - (x+2) (x+2)

= (x+2) (x-2 - x-2)

= -4 (x+2)

e: \(=x^2-16-2x^2-6x+x^2+6x+9=-7\)

b: \(=\left(6x+1-6x+1\right)^2=2^2=4\)

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

\(A\left(x\right)=\dfrac{1}{4}x^3+\dfrac{11}{3}x^2-6x-\dfrac{2}{3}x^2+\dfrac{7}{4}x^3+2x+3\)
\(=\left(\dfrac{1}{4}x^3+\dfrac{7}{4}x^3\right)+\left(\dfrac{11}{3}x^2-\dfrac{2}{3}x^2\right)-\left(6x-2x\right)+3\)
\(=2x^3+3x^2-4x+3\)

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

giúp với trí ơi

giúp nốt trí ui

a) \(4x^2-2x-y^2-y=\left(4x^2-y^2\right)-\left(2x+y\right)\)

\(=\left(2x+y\right)\left(2x-y\right)-\left(2x+y\right)=\left(2x+y\right)\left(2x-y-1\right)\)

b) \(9x^2-25y^2-6x+10y=\left(3x-5y\right)\left(3x-5y\right)-2\left(3x-5y\right)\)

\(=\left(3x-5y\right)\left(3x+5y-2\right)\)

c) \(x^3-2x^2+2x-1=x^3-1-2x^2+2x\)

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

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

d) \(x^4+2x^3-4x-4=x^4-4+2x^3-4x\)

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

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

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