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)