Toán Lớp 8: ) Phân tích các đa thức sau thành nhân tử:
a) x^2 y-2xy^2+y^3
b) 4×3 – 8×2 + 4x
c) x(x + y) – 8x – 8y
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Toán Lớp 8: ) Phân tích các đa thức sau thành nhân tử:
a) x^2 y-2xy^2+y^3
b) 4×3 – 8×2 + 4x
c) x(x + y) – 8x – 8y
Comments ( 2 )
a) x^2 y-2xy^2+y^3
=y(x^2-2xy+y^2)
=y(x-y)^2
b) 4x^3 – 8x^2 + 4x
=4x(x^2-2+1)
=4x(x-1)^2
c) x(x + y) – 8x – 8y
=x(x+y)-(8x+8y)
=x(x+y)-8(x+y)
=(x+y)(x-8)
$a)$ $x^2y-2xy^2+y^3$
$=y\left(x^2-2xy+y^2\right)$
$=y\left(x-y\right)\left(x-y\right)$
$=y\left(x-y\right)^2$
$b)$ $x^4x^3-8x^2+4x$
$=x^{4+3}-8x^2+4x$
$=x^7-8x^2+4x$
$=x^6x-8xx+4x$
$=x\left(x^6-8x+4\right)$
$c)$ $x\left(x+y\right)-8x-8y$
$=xx+xy-8x-8y$
$=x^2+xy-8x-8y$
$=\left(x^2+xy\right)+\left(-8x-8y\right)$
$=x\left(x+y\right)-8\left(x+y\right)$
$=\left(x+y\right)\left(x-8\right)$