a (3-2x)2 = 6 - 4x

b (xy+5)2 = 2xy + 10

c (2x+1)(1-2x) = 2x - 4x² + 1 - 2x = 4x2 + 1

d (1-5x)3 = 3-15x

e (2x+y)(4x2 - 4xy + y2) = 8x³ -8x²y+2xy² + 4x²y-4xy² + y³ = 8x³ + y³ - 4x²y - 2xy²

`a, (3x+4)^2 = 9x^2 + 24x + 16`

`b, (5x-y)^2 = 25x^2 - 10xy + y^2`

`c, (xy - 1/2y)^2 = x^2y^2 - xy^2 + 1/4y^2`

a) \(\dfrac{x^2-2x+1-x^2-2x-1+4}{\left(x+1\right)\left(x-1\right)}=\dfrac{-4\left(x-1\right)}{\left(x+1\right)\left(x-1\right)}=\dfrac{-4}{x+1}\)

\(\dfrac{xy\left(x^2+y^2\right)}{xy\left(x^3\right)}.\dfrac{1}{x^2+y^2}=\dfrac{1}{x^3}\)

a) Ta có: \(\dfrac{x-1}{x+1}-\dfrac{x+1}{x-1}+\dfrac{4}{x^2-1}\)

\(=\dfrac{\left(x-1\right)^2}{\left(x+1\right)\left(x-1\right)}-\dfrac{\left(x+1\right)^2}{\left(x+1\right)\left(x-1\right)}+\dfrac{4}{\left(x-1\right)\left(x+1\right)}\)

\(=\dfrac{x^2-2x+1-x^2-2x-1+4}{\left(x+1\right)\left(x-1\right)}\)

\(=\dfrac{-4x+4}{\left(x+1\right)\left(x-1\right)}\)

\(=\dfrac{-4\left(x-1\right)}{\left(x+1\right)\left(x-1\right)}=\dfrac{-4}{x+1}\)

a: =1/2x^3*x^2-1/2x^3*6x-1/2x^3*10

=1/2x^5-3x^4-5x^3

b: =-3x^2*5x^3+3x^2*4x^2-3x^2*3x+3x^2*3x

=-15x^5+12x^4-9x^3+9x^2

c: \(=3x\cdot5x^2-3x\cdot2x-3x=15x^3-6x^2-3x\)

d: \(=\dfrac{1}{2}x^2y\cdot2x^3-\dfrac{1}{2}x^2y\cdot\dfrac{2}{5}xy^2-\dfrac{1}{2}x^2y=x^5y-\dfrac{1}{5}x^3y^3-\dfrac{1}{2}x^2y\)

`a, (3x+1)^2 = 9x^2 + 6x + 1`.

`b, (4x+5y)^2 = 16x^2 + 20xy + 25y^2`

`c, (5x-1/2)^2 = 25x^2 - 5x + 1/4`

`d, (-x+2y^2)^2 = x^2 - 2y^2x + 4y^4`.

`a)`

`(3x + 1)^2`

`= 9x^2 + 6x + 1`

`b)`

`(4x + 5y)^2`

`= 16x^2 + 40xy + 25y^2`

`c)`

`(5x - 1/2)^2`

`= 25x^2 - 5x + 1/4`

`d)`

`(-x + 2y^2)^2`

`= x^2 - 4xy^2 + 4y^4`

\(a,=4x^2+12xy+9y^2\\ b,=25x^2-10xy+y^2\\ d,=4x^2+4xy^2+y^4\\ e,=9x^4-12x^2y+4y^2\\ g,=x^3+64\)

a) x-y

b) 8x²+x

c) 1

a. (3a + 1)³

= 27a³ + 27a² + 9a + 1