Phân tích đa thức sau thành nhân tử : a, 2x ³-8x²+8x b, x ²y-x ³-9y+9x c, 2x ²-3x-5 06/12/2021 Bởi Brielle Phân tích đa thức sau thành nhân tử : a, 2x ³-8x²+8x b, x ²y-x ³-9y+9x c, 2x ²-3x-5
a, $2x^3-8x^2+8x=2x(x^2-4x+4)=2x(x-2)^2$ b, $x^2y-x^3-9y+9x=x^2(y-x)-9(y-x)$ $=(x^2-9)(y-x)=(x-3)(x+3)(y-x)$ c, $2x^2-3x-5=2x^2+2x-5x-5$ $=2x(x+1)-5(x+1)=(2x-5)(x+1)$ Bình luận
a, 2x ³-8x²+8x =2x(x²-4x+4) =2x(x-2)² b, x ²y-x ³-9y+9x =(x ²y-x ³)-(9y-9x) =x²(y-x)-9(y-x) =(x²-9)(y-x) =(x+3)(x-3)(y-x) c, 2x ²-3x-5 =2x²-2x+5x-5 =(2x²-2x)+(5x-5) =2x(x-1)+5(x-1) =(x-1)(2x+5) Bình luận
a, $2x^3-8x^2+8x=2x(x^2-4x+4)=2x(x-2)^2$
b, $x^2y-x^3-9y+9x=x^2(y-x)-9(y-x)$
$=(x^2-9)(y-x)=(x-3)(x+3)(y-x)$
c, $2x^2-3x-5=2x^2+2x-5x-5$
$=2x(x+1)-5(x+1)=(2x-5)(x+1)$
a, 2x ³-8x²+8x
=2x(x²-4x+4)
=2x(x-2)²
b, x ²y-x ³-9y+9x
=(x ²y-x ³)-(9y-9x)
=x²(y-x)-9(y-x)
=(x²-9)(y-x)
=(x+3)(x-3)(y-x)
c, 2x ²-3x-5
=2x²-2x+5x-5
=(2x²-2x)+(5x-5)
=2x(x-1)+5(x-1)
=(x-1)(2x+5)