Phân tích đa thức thành nhân tử: a) $4x^{2}$$y-2xy$ b) $25-x^{2}$$-2xy-y^{2}$ c) $x^{2}$$-4x-y^{2}$$+4$ 04/12/2021 Bởi Mackenzie Phân tích đa thức thành nhân tử: a) $4x^{2}$$y-2xy$ b) $25-x^{2}$$-2xy-y^{2}$ c) $x^{2}$$-4x-y^{2}$$+4$
`~rai~` $\begin{array}{I} a)4x^2y-2xy\\=2xy(2x-1).\\b)25-x^2-2xy-y^2\\=25-(x+y)^2\\=(5+x+y)(5-x-y).\\c)x^2-4x-y^2+4\\=(x^2-4x+4)-y^2\\=(x-2)^2-y^2\\=(x+y-2)(x-y-2).\end{array}$ Bình luận
a 4x2y – 2xy = 2xy ( 2x – 1 ) b, 25 – x2 -2xy – y2 = 25 – ( x2 +2xy+y2) = 25 – ( x+y )^2 = 5 ^2 – (x+y ) ^2 = (5-x+y)(5-x-y) c,x2-4x-y2+4 =(x2-4x+4)-y2 =(x-2)^2 – y2 = (x-2-y)(x-2+y) Bình luận
`~rai~`
$\begin{array}{I} a)4x^2y-2xy\\=2xy(2x-1).\\b)25-x^2-2xy-y^2\\=25-(x+y)^2\\=(5+x+y)(5-x-y).\\c)x^2-4x-y^2+4\\=(x^2-4x+4)-y^2\\=(x-2)^2-y^2\\=(x+y-2)(x-y-2).\end{array}$
a 4x2y – 2xy
= 2xy ( 2x – 1 )
b, 25 – x2 -2xy – y2
= 25 – ( x2 +2xy+y2)
= 25 – ( x+y )^2
= 5 ^2 – (x+y ) ^2
= (5-x+y)(5-x-y)
c,x2-4x-y2+4
=(x2-4x+4)-y2
=(x-2)^2 – y2
= (x-2-y)(x-2+y)