x3-2x2+x 2x2+4x+2-2y2 2xy-x2-y2+16

2 câu trả lời

Đáp án + Giải thích các bước giải:

 a)x3-2x2+x

=x(x2-2x+1)

=x(x-1)2

b)2x2+4x+2-2y2

=2(x2+2x+1-y2)

=2[(x2+2x+1)-y2]

=2[(x+1)2-y2]

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

c)2xy-x2-y2+16

=16-(x2-2xy+y2)

=42-(x-y)2

=(4-x+y)(4+x-y)

+, x3-2x2+x

=x(x2-2x+1)

=x(x-1)2

+, 2x2+4x+2-2y2

=2(x2+2x+1-y2)

=2[(x2+2x+1)-y2]

=2[(x+1)2-y2]

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

+, 2xy-x2-y2+16

=-(-2xy+x2+y2-16)

=-(x2-2xy+y2-16)

=-[(x2-2xy+y2)-16]

=-[(x-y)2-42]

=-(x-y-4)(x-y+4)