Thực hiên phép tính
Câu 1 : Thực hiên phép tính :
a) ( y - 3 ) ( y + 3 ) ( y^2 + 9 ) - ( y^2 + 2 ) ( y^2 - 2 )
b) -21xy^5z^3 : 7xy^2z^3
c) ( 1 + 3x )^2 + ( 3x + 5 )^2 - 2( 3x + 1 ) ( 3x+ 5 )
d) ( 5xy^2 + 9xy - x^2y^2 ) : ( -xy )
Câu 2 : Chứng minh rằng :
a) ( x - y ) ( x^4 + x^3y + x^2y^2 + xy^3 + y^4 ) = x^5 - y^5
b) ( x + 1 )^3 - ( x - 1 )^3 - 6( x + 1 ) ( x - 1 ) = 8
a) ( y - 3 ) ( y + 3 ) ( y^2 + 9 ) - ( y^2 + 2 ) ( y^2 - 2 )
b) -21xy^5z^3 : 7xy^2z^3
c) ( 1 + 3x )^2 + ( 3x + 5 )^2 - 2( 3x + 1 ) ( 3x+ 5 )
d) ( 5xy^2 + 9xy - x^2y^2 ) : ( -xy )
Câu 2 : Chứng minh rằng :
a) ( x - y ) ( x^4 + x^3y + x^2y^2 + xy^3 + y^4 ) = x^5 - y^5
b) ( x + 1 )^3 - ( x - 1 )^3 - 6( x + 1 ) ( x - 1 ) = 8