Toán x^2-3x-4y^2+6y x^2-25y^2-6x+9 x^2-x+3-3x 02/07/2021 By Melanie x^2-3x-4y^2+6y x^2-25y^2-6x+9 x^2-x+3-3x
`a)x^2-3x-4y^2+6y` `=(x^2-4y^2)-(3x-6y)` `=(x-2y)(x+2y)-3(x-2y)` `=(x-2y)(x+2y-3)` `b)x^2-25y^2-6x+9` `=(x^2-6x+9)-25y^2` `=(x-3)^2-(5y)^2` `=(x-3+5y)(x-3-5y)` `c)x^2-x+3-3x` `=(x^2-x)+(3-3x)` `=-x(1-x)+3(1-x)` `=(1-x)(3-x)` Trả lời
a/ $x^2-3x-4y^2+6y\\=(x^2-4y^2)-(3x-6y)\\=(x-2y)(x+2y)-3(x-2y)\\=(x-2y)(x+2y-3)$ b/ $x^2-25y^2-6x+9\\=(x^2-6x+9)-25y^2\\=(x-3)^2-25y^2\\=(x-5y-3)(x+5y-3)$ c/ $x^2-x+3-3x\\=(x^2-x)-(3x-3)\\=x(x-1)-3(x-1)\\=(x-3)(x-1)$ Trả lời
`a)x^2-3x-4y^2+6y`
`=(x^2-4y^2)-(3x-6y)`
`=(x-2y)(x+2y)-3(x-2y)`
`=(x-2y)(x+2y-3)`
`b)x^2-25y^2-6x+9`
`=(x^2-6x+9)-25y^2`
`=(x-3)^2-(5y)^2`
`=(x-3+5y)(x-3-5y)`
`c)x^2-x+3-3x`
`=(x^2-x)+(3-3x)`
`=-x(1-x)+3(1-x)`
`=(1-x)(3-x)`
a/ $x^2-3x-4y^2+6y\\=(x^2-4y^2)-(3x-6y)\\=(x-2y)(x+2y)-3(x-2y)\\=(x-2y)(x+2y-3)$
b/ $x^2-25y^2-6x+9\\=(x^2-6x+9)-25y^2\\=(x-3)^2-25y^2\\=(x-5y-3)(x+5y-3)$
c/ $x^2-x+3-3x\\=(x^2-x)-(3x-3)\\=x(x-1)-3(x-1)\\=(x-3)(x-1)$