đa thức x^2 -4x+x (x+y)^2-(x-y)^2 (4x+2)x(4x-2) thành nhân tử 21/11/2021 Bởi Alexandra đa thức x^2 -4x+x (x+y)^2-(x-y)^2 (4x+2)x(4x-2) thành nhân tử
a,$x²-4x+x$ $=x²-3x$ $=x(x-3)$ b,$(x+y)²-(x-y)²$ $=(x+y+x-y)(x+y-x+y)$ $=2x.2y$ $=4xy$ c,$(4x+2)x(4x-2)$ $=x(16x²-4)$ Bình luận
`x^2 -4x+x` `=x^2-(4x-x)` `=x^2-3x` `(x+y)^2-(x-y)^2` `=(x^2 +2xy+y^2)-(x^2-2xy+y^2)` `=x^2 +2xy+y^2-x^2+2xy-y^2` `=4xy` `(4x+2)x(4x-2)` `=4(4x-2).x^2+2x(4x-2)` `=16x^3-8x^2+2x(4x-2)` `=16x^3-8x^2+8x^2-4x` `=16x^3-(8x^2+8x^2)-4x` `=16x^3-4x` Bình luận
a,$x²-4x+x$
$=x²-3x$
$=x(x-3)$
b,$(x+y)²-(x-y)²$
$=(x+y+x-y)(x+y-x+y)$
$=2x.2y$
$=4xy$
c,$(4x+2)x(4x-2)$
$=x(16x²-4)$
`x^2 -4x+x`
`=x^2-(4x-x)`
`=x^2-3x`
`(x+y)^2-(x-y)^2`
`=(x^2 +2xy+y^2)-(x^2-2xy+y^2)`
`=x^2 +2xy+y^2-x^2+2xy-y^2`
`=4xy`
`(4x+2)x(4x-2)`
`=4(4x-2).x^2+2x(4x-2)`
`=16x^3-8x^2+2x(4x-2)`
`=16x^3-8x^2+8x^2-4x`
`=16x^3-(8x^2+8x^2)-4x`
`=16x^3-4x`