x6 - y6
= ( x2 )3 - ( y2 )3
= ( x2 - y2 ) ( x4 + x2y2 + y4 )
HĐT 7 : A3 - B3
x3y6z9 + 1
= ( xy2z3)3 + 1
= ( xy2z3 + 1 ) ( x2y4z6 + zy2z3 + 1 )
HĐT 6
Ta có : x6 - x6
= ( x2)3 - ( y2)3
= ( x2 - y2 ) ( x4 + x2y2 + y4 )
= (x - y)(x + y) ( x4 + x2y2 + y4 )
Ta có : x6 - x6
= ( x2)3 - ( y2)3
= ( x2 - y2 ) ( x4 + x2y2 + y4 )
= (x - y)(x + y) ( x4 + x2y2 + y4 )
hok tốt