ĐỀ BÀI : khai triển các hằng đẳng thức

a.( x - 1 ) mũ 3 =

b. ( 1 + y ) mũ 3 =

c. x mũ 3 + y mũ 3 =

d. a mũ 3 - 1 =

e. a mũ 3 + 8 =

f. ( x + 1 ) ( x mũ 2 - x + 1 )

g . ( ........................+...................) mũ 2 =x mũ 2 + ........................ + 4 y mũ 4 

h. ( 1 - x ) ( 1 + x + x mũ 2 ) =...............

i. ( ...................... - ............... ) mũ 2  = a mũ 2 - 6ab + ..................

k. ( x - 2 ) ( x mũ 2 + 2x + 4 )= ...................

l. ( .................... + ...........................) mũ 2 = ............................+ m + 1 phần 4

m. a mũ 3 + 3a mũ 2 + 3a + 1=...........................

$Thenny$ 

a) $( x - 1 )^{3}$ = $x^{3}$ - $3x^{2}$ + $3x$ - 1

b) $( 1 + y )^{3}$ = 1 + $3y + 3y^{2}$ + $y^{3}$ 

c) $x^{3}$ + $y^{3}$ = $( x + y )$$(x^{2} - xy + y^{2})$ 

d) $a^{3} − 1 = ( a^{2} − 1 ) (a^{2} + a + 1 )$ 

e) $a^{3} + 8 = ( a^{2} + 8 ) (a^{2} - 8a + 64 )$ 

f) $( x + 1 )( x^{2} - x + 1) = x^{3} + 1$

g) $( x + 2y^{2} )^{2} = x^{2} + 4xy^{2} + 4y^{4}$

h) $( 1 - x )( 1 + x + x^{2} ) = 1 - x^{3}$

i) $( a - 3b )^{2} = a^{2} - 6ab + 9b^{2}$

k) $( x - 2 )( x^{2} + 2x + 4 ) = x^{3} - 8$

l ) $( x + \frac{1}{2})^{2} = x^{2} + x + \frac{1}{4}$ 

m) $a^{3} + 3a{2} + 3a + 1 = ( a + 1 )^3$

$Humiza$

a)

$( x - 1 )^{3}$ = $x^{3}$ - $3x^{2}$ + $3x$ - $1$

b)

$( 1 + y )^{3}$ = 1 + $3y + 3y^{2}$ + $y^{3}$ 

c)

$x^{3}$ + $y^{3}$ = $( x + y )$$(x^{2} - xy + y^{2})$ 

d)

$a^{3} − 1 = ( a^{2} − 1 ) (a^{2} + a + 1 )$ 

e)

$a^{3} + 8 = ( a^{2} + 8 ) (a^{2} - 8a + 64 )$ 

f)

$( x + 1 )( x^{2} - x + 1) = x^{3} + 1$

g)

$( x + 2y^{2} )^{2} = x^{2} + 4xy^{2} + 4y^{4}$

h)

$( 1 - x )( 1 + x + x^{2} ) = 1 - x^{3}$

i)

$( a - 3b )^{2} = a^{2} - 6ab + 9b^{2}$

k)

$( x - 2 )( x^{2} + 2x + 4 ) = x^{3} - 8$

l )

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

m)

$a^{3} + 3a{2} + 3a + 1 = ( a + 1 )^3$