phân tích đa thức thành nhân tử bằng PP đặt nhân tử chung a) 10xy.(x-y)-6y.(y-x) b) x^2 -9-2.(x+3)^2 04/07/2021 Bởi Allison phân tích đa thức thành nhân tử bằng PP đặt nhân tử chung a) 10xy.(x-y)-6y.(y-x) b) x^2 -9-2.(x+3)^2
`a, 10xy·(x-y)-6y·(y-x)` `=10xy·(x-y)+6y(x-y)` `=2y(x-y)(5x+3)` `b, x^2-9-2·(x+3)^2` `=(x-3)(x+3)-2·(x+3)^2` `=(x+3)[(x-3)-2(x+3)]` `=(x+3)(x-3-2x-6)` `=(x+3)(-x-9)` `=-(x+3)(x+9)` Bình luận
Đáp án: $a, 10xy(x – y) – 6y(y – x) $ $= 10xy(x – y) + 6y(x – y) $ $= (10xy + 6y)(x – y) $ $= 2y(5x + 3)(x – y) $ $b, x² – 9 – 2(x + 3)² $ $= (x – 3)(x + 3) – 2(x + 3)² $ $= (x + 3)[(x – 3) – 2(x + 3)] $ $= (x + 3)(x – 3 – 2x – 6) $ $= (x + 3)(-x – 9) $ Bình luận
`a, 10xy·(x-y)-6y·(y-x)`
`=10xy·(x-y)+6y(x-y)`
`=2y(x-y)(5x+3)`
`b, x^2-9-2·(x+3)^2`
`=(x-3)(x+3)-2·(x+3)^2`
`=(x+3)[(x-3)-2(x+3)]`
`=(x+3)(x-3-2x-6)`
`=(x+3)(-x-9)`
`=-(x+3)(x+9)`
Đáp án:
$a, 10xy(x – y) – 6y(y – x) $
$= 10xy(x – y) + 6y(x – y) $
$= (10xy + 6y)(x – y) $
$= 2y(5x + 3)(x – y) $
$b, x² – 9 – 2(x + 3)² $
$= (x – 3)(x + 3) – 2(x + 3)² $
$= (x + 3)[(x – 3) – 2(x + 3)] $
$= (x + 3)(x – 3 – 2x – 6) $
$= (x + 3)(-x – 9) $