Phân tích thành nhân tử:
a) x4+4y4
b) x3+4x4-29x+24
Phân tích đa thức thành nhân tử:
a)x3-8x2+16x
b)x2+4y2+2x-4y-4xy-24
c)x4+x3-x2-2x-2
`a)x^3-8x^2+16x`
`=x(x^2-8x+16)`
`=x(x-4)^2`
`b)x^2+4y^2+2x-4y-4xy-24`
`=(x-2y)^2+2(x-2y)-24`
`=(x-2y)^2-4(x-2y)+6(x-2y)-24`
`=(x-2y-4)(x-2y+6)`
`c)x^4+x^3-x^2-2x-2`
`=x^4-2x^2+x^3-2x+x^2-2`
`=x^2(x^2-2)+x(x^2-2)+x^2-2`
`=(x^2-2)(x^2+x+1)`
Bài 1: Phân tích các đa thức sau thành nhân tử
a)x2-y2-2x+2y e)x4+4y4
b)x2(x-1)+16(1-x) f)x4-13x2+36
c)x2+4x-y2+4 g) (x2+x)2+4x2+4x-12
d)x3-3x2-3x+1 h)x6+2x5+x4-2x3-2x2+1
a.
$x^2-y^2-2x+2y=(x^2-y^2)-(2x-2y)=(x-y)(x+y)-2(x-y)=(x-y)(x+y-2)$
b.
$x^2(x-1)+16(1-x)=x^2(x-1)-16(x-1)=(x-1)(x^2-16)=(x-1)(x-4)(x+4)$
c.
$x^2+4x-y^2+4=(x^2+4x+4)-y^2=(x+2)^2-y^2=(x+2-y)(x+2+y)$
d.
$x^3-3x^2-3x+1=(x^3+1)-(3x^2+3x)=(x+1)(x^2-x+1)-3x(x+1)$
$=(x+1)(x^2-4x+1)$
e.
$x^4+4y^4=(x^2)^2+(2y^2)^2+2.x^2.2y^2-4x^2y^2$
$=(x^2+2y^2)^2-(2xy)^2=(x^2+2y^2-2xy)(x^2+2y^2+2xy)$
f.
$x^4-13x^2+36=(x^4-4x^2)-(9x^2-36)$
$=x^2(x^2-4)-9(x^2-4)=(x^2-9)(x^2-4)=(x-3)(x+3)(x-2)(x+2)$
g.
$(x^2+x)^2+4x^2+4x-12=(x^2+x)^2+4(x^2+x)-12$
$=(x^2+x)^2-2(x^2+x)+6(x^2+x)-12$
$=(x^2+x)(x^2+x-2)+6(x^2+x-2)=(x^2+x-2)(x^2+x+6)$
$=[x(x-1)+2(x-1)](x^2+x+6)=(x-1)(x+2)(x^2+x+6)$
h.
$x^6+2x^5+x^4-2x^3-2x^2+1$
$=(x^6+2x^5+x^4)-(2x^3+2x^2)+1$
$=(x^3+x^2)^2-2(x^3+x^2)+1=(x^3+x^2-1)^2$
Phân tích đa thức thành nhân tử:
a) 2x-72x3
b) m3p+m2np-m2p2-mnp2
c) a(x2+4)-x(a2+4)
d) (xy+ab)2+(ay-bx)2
e) x2y-xy2+x3-y3
f) 4x4+1
Phân tích đa thức thành nhân tử:
a) x4+4 b) x8+x7+1
c) x8+x4+1 d) x5+x+1
e) x2+2x2-24 f) a4+4b4
a: \(x^4+4=\left(x^2-2x+2\right)\left(x^2+2x+2\right)\)
b: \(x^8+x^7+1\)
\(=x^8+x^7+x^6-x^6-x^5-x^4+x^5+x^4+x^3-x^3-x^2-x+x^2+x+1\)
\(=\left(x^2+x+1\right)\left(x^6-x^4+x^3-x+1\right)\)
c: \(x^8+x^4+1\)
\(=\left(x^8+2x^4+1\right)-x^4\)
\(=\left(x^4-x^2+1\right)\cdot\left(x^4+x^2+1\right)\)
\(=\left(x^4-x^2+1\right)\left(x^2+1-x\right)\left(x^2+1+x\right)\)
a)\(x^4+4\\ =\left(x^2\right)^2+4x^2+4-4x^2\\ =\left[\left(x^2\right)^2+4x^2+4\right]-\left(2x\right)^2\\ =\left(x^2+2\right)^2-\left(2x\right)^2\\ =\left(x^2+2+2x\right)\left(x^2+2-2x\right)\)
\(a)\; x^4+4 \\= x^4+4x^2+4-4x^2\\=(x^2+2)^2-4x^2\\=(x^2+2-2x)(x^2+2+2x)\)
Phân tích đa thức thành nhân tử:
a) 2x-72x3
b) m3p+m2np-m2p2-mnp2
c) a(x2+4)-x(a2+4)
d) (xy+ab)2+(ay-bx)2
e) x2y-xy2+x3-y3
f) 4x4+1
(Mình cần gấp ạ :3)
a) \(2x-72x^3=2x\left(1-36x^2\right)=2x\left(1-6x\right)\left(1+6x\right)\)
f) \(4x^4+1=4x^4+4x^2+1-4x^2=\left(2x^2+1\right)^2-\left(2x\right)^2=\left(2x^2-2x+1\right)\left(2x^2+2x+1\right)\)
Phân tích đa thức thành nhân tử:
a) xy + y2 – x – y
b) 25 – x2 + 4xy – 4y2
c) 4x3 + 4xy2 + 8x2y – 16x
d) (x2 + x)2 + 4(x2 + x) – 12
e) (x + 1) (x + 2) (x + 3) (x + 4) - 24 g)
h) x2 – 5x + 4
i) x4 – 5x2 + 4
j) x3 – 2x2 + 6x – 5
k) x2 – 4x + 3
a: \(=x\left(x+y\right)-\left(x+y\right)=\left(x+y\right)\left(x-1\right)\)
b: \(=25-\left(x-2y\right)^2\)
\(=\left(5-x+2y\right)\left(5+x-2y\right)\)
Phân tích đa thức thành nhân tử:
a.10x2y – 20xy2 b. x2 – y2 + 10y – 25 c. x2 – y2 + 3x – 3y
d. x3 + 3x2 – 16x – 48 e. 9x3 + 6x2 + x f. x4 + 5x3 + 15x – 9
\(a,10x^2y-20xy^2=10xy\left(x-2y\right)\\ b,x^2-y^2+10y-25=x^2-\left(y^2-10y+25\right)=x^2-\left(y-5\right)^2=\left(x-y+5\right)\left(x+y-5\right)\\ c,x^2-y^2+3x-3y=\left(x-y\right)\left(x+y\right)+3\left(x-y\right)=\left(x-y\right)\left(x+y+3\right)\\ d,x^3+3x^2-16x-48=\left(x^3+3x^2\right)-\left(16x+48\right)=x^2\left(x+3\right)-16\left(x+3\right)=\left(x+3\right)\left(x^2-16\right)=\left(x+3\right)\left(x+4\right)\left(x-4\right)\)
\(e,9x^3+6x^2+x=x\left(9x^2+6x+1\right)=x\left(3x+1\right)^2\\ f,x^4+5x^3+15x-9=\left(x^4+5x^3-3x^2\right)+\left(3x^2+15x-9\right)=x^2\left(x^2+5x-3\right)+3\left(x^2+5x-3\right)=\left(x^2+3\right)\left(x^2+5x-3\right)\)
phân tích thành nhân tử:
a)x4+ 2x3+ x2
Phân tích đa thức thành nhân tử:
A= x4 + 4.
\(x^4+4\)
\(=x^4+4x^2+4-4x^2\)
\(=\left(x^2+2\right)^2-4x^2\)
\(=\left(x^2+2x+2\right)\left(x^2-2x+2\right)\)
\(A=x^4+4\)
\(=\) \(x^4+4+4x^2-4x^2\)
\(=\left(x^2+2\right)^2-4x^2\)
\(A=\) \(\left(x^2+2-2x\right)\left(x^2+2+2x\right)\)
Bài 1: Phân tích đa thức thành nhân tử:
a) x2y+xy+x+1
b) x2-(a+b)x+ab
c) ax2+ay-bx2-by
d) ax-2x-a2+2a
e) 2x2+4ax+x+2a
f) x3+ax2+x+a
g) x4+2x3-4x-4
a) x2y+xy+x+1= (x2y+xy)+(x+1)=xy(x+10+(x+1)=(x+1)(xy+1)
b) x2-(a+b)x+ab=x2-ax-bx+ab=(x2-ax)-(bx-ab)=x(x-a)-b(x-a)=(x-a)(x-b)
c) ax2+ay-bx2-by=(ax2+ay)-(bx2+by)=a(x2+y)-b(x2+y)=(a-b)(x2+y)
d) ax-2x-a2+2a=(ax-2x)-(a2-2a)=x(a-2)-a(a-2)=(a-2)(x-a)
e) 2x2+4ax+x+2a=(2x2+4ax)+(x+2a)=2x(x+2a)+(x+2a)=(x+2a)(2x+1)
f) x3+ax2+x+a=(x3+ax2)+(x+a)=x2(x+a)+(x+a)=(x2+1)(x+a)
g: Ta có: \(x^4+2x^3-4x-4\)
\(=\left(x^2-2\right)\left(x^2+2\right)-2x\left(x^2-2\right)\)
\(=\left(x^2-2\right)\cdot\left(x^2+2x+2\right)\)