Phân tích đa thức sau thành nhân tử:
9x^2-9y^2-6x+1
Tìm x
a)4x^2(x-2016)-x+2016=0
b)x^2-5x+6=12
Phân tích các đa thức sau thành nhân tử
1) x^3+2x-3
2) x^3-6x+4
3) x^3-2x^2+1
4)x^3+5x^2-12
5) x^3-6x+9x
6) 4x^3-9x^2+5x
1) \(x^3+2x-3\)
\(=\left(x^3-x^2\right)+\left(x^2-x\right)+\left(3x-3\right)\)
\(=x^2\left(x-1\right)+x\left(x-1\right)+3\left(x-1\right)\)
\(=\left(x-1\right)\left(x^2+x+3\right)\)
2) \(x^3-6x+4\)
\(=\left(x^3-2x^2\right)+\left(2x^2-4x\right)-\left(2x-4\right)\)
\(=x^2\left(x-2\right)+2x\left(x-2\right)-2\left(x-2\right)\)
\(=\left(x-2\right)\left(x^2+2x-2\right)\)
3) \(x^3-2x^2+1\)
\(=\left(x^3-x^2\right)-\left(x^2-x\right)-\left(x-1\right)\)
\(=x^2\left(x-1\right)-x\left(x-1\right)-\left(x-1\right)\)
\(=\left(x-1\right)\left(x^2-x-1\right)\)
4) \(x^3+5x^2-12\)
\(=\left(x^3+2x^2\right)+\left(3x^2+6x\right)-\left(6x+12\right)\)
\(=x^2\left(x+2\right)+3x\left(x+2\right)-6\left(x+2\right)\)
\(=\left(x+2\right)\left(x^2+3x-6\right)\)
5) \(x^3-6x^2+9x\) (chắc đề như vậy)
\(=x\left(x^2-6x+9\right)\)
\(=x\left(x-3\right)^2\)
6) \(4x^3-9x^2+5x\)
\(=x\left(4x^2-9x+5\right)\)
\(=x\left[\left(4x^2-4x\right)-\left(5x-5\right)\right]\)
\(=x\left[4x\left(x-1\right)-5\left(x-1\right)\right]\)
\(=x\left(x-1\right)\left(4x-5\right)\)
phân tích thành nhân tử
\(4x^3 -4x^2 -9x+9\)
\(x^3 +6x^2 +11x+6\)
\(x^2 y-x^3 -9y+9x\)
`@` `\text {Ans}`
`\downarrow`
`4x^3 - 4x^2 - 9x + 9`
`= (4x^3 - 4x^2) - (9x - 9)`
`= 4x^2(x - 1) - 9(x - 1)`
`= (4x^2 - 9)(x - 1)`
____
`x^3 + 6x^2 + 11x + 6`
`= x^3 + x^2 + 5x^2 + 5x + 6x + 6`
`= (x^3 + x^2) + (5x^2 + 5x) + (6x + 6)`
`= x^2*(x + 1) + 5x(x + 1) + 6(x + 1)`
`= (x^2 + 5x + 6)(x+1)`
____
`x^2y - x^3 - 9y + 9x`
`= (x^2y - 9y) - (x^3 - 9x)`
`= y(x^2 - 9) - x(x^2 - 9)`
`= (y - x)(x^2 - 9)`
b: =x^3+x^2+5x^2+5x+6x+6
=(x+1)(x^2+5x+6)
=(x+1)(x+2)(x+3)
c: =x^2(y-x)-9(y-x)
=(y-x)(x^2-9)
=(y-x)(x-3)(x+3)
a: =(4x^3-4x^2)-(9x-9)
=4x^2(x-1)-9(x-1)
=(x-1)(4x^2-9)
=(x-1)(2x-3)(2x+3)
Phân tích đa thức sau thành nhân tử a.(x^2+1)^2-x^2 b.(x^2-6xy)+9y^2 c.5x^3-10x^2y+5xy^2 d.x^2-6x+9 e.4x(2y-z)-7y(z-2y)
a: =(x^2-x+1)(x^2+x+1)
b: =x^2-6xy+9y^2=(x-3y)^2
c: =5x(x^2-2xy+y^2)
=5x(x-y)^2
d: =(x-3)^2
e: =(2y-z)(4x+7y)
a)HĐT:(x^2+1-x)(x^2+1+x)
b)=x^2-2.x.3y+(3y)^2
c)=5x(x^2-2xy+y^2)
=5x(x-y)^2
d)x^2-2.3.x+3^2
=(x-3)^2
e)(2y-z)+7y(2y-z)
=(2y-z)(1+7y)
CÂU 3: PHÂN TÍCH ĐA THỨC THÀNH NHÂN TỬ:
A) 3x^3-6x^2+3x
B) 16x^2y-4xy^2-4x^3
C) x^2+4x+4-9y^2
D) x^2-5x-6
\(a,3x^3-6x^2+3x\)
\(=3x\left(x^2-2x+1\right)\)
\(=3x\left(x-1\right)^2\)
\(b,16x^2y-4xy^2-4x^3\)
\(=-4x\left(x^2-4xy+4y^2-3y^2\right)\)
\(=-4x\left(x-2y+y\sqrt{3}\right)\left(x-2y-y\sqrt{3}\right)\)
Phân tích đa thức sau thành nhân tử: a) x^2-4x+4-y^2 b) x^2+6x-4y^2+9 c) x^2-6xy+9y^2-36
a) = (x - 2)2 - y2
= (x - 2 - y)(x + 2 + y)
b) = (x^2 + 6x + 9) - (2y)^2
= (x + 3)2 - (2y)2
= (x - 2y + 3)(x + 2y + 3)
c) = (x - 3y)2 - 62
= (x - 3y - 6)(x - 3y + 6)
phân tích các đa thức sau thành nhân tử
a, x^2 - xz - 9y^2 + 3yz
b, x^3 - x^2 - 5x +125
c, x^3 + 2x^2 - 6x - 27
d, 12x^3 + 4x^2 - 27x - 9
a) \(x^2-xz-9y^2+3yz\)
\(=\left(x^2-9y^2\right)-\left(xz-3yz\right)\)
\(=\left(x-3y\right)\left(x+3y\right)-z\left(x-3y\right)\)
\(=\left(x-3y\right)\left(x+3y-z\right)\)
c) \(x^3+2x^2-6x-27\)
\(=\left(x^3-27\right)+\left(2x^2-6x\right)\)
\(=\left(x-3\right)\left(x^2-3x+9\right)+2x\left(x-3\right)\)
\(=\left(x-3\right)\left(x^2-3x+9+2x\right)\)
\(=\left(x-3\right)\left(x^2-x+9\right)\)
b) \(x^3-x^2-5x+125\)
\(=\left(x^3+125\right)-\left(x^2+5x\right)\)
\(=\left(x+5\right)\left(x^2-5x+25\right)-x\left(5+x\right)\)
\(=\left(x+5\right)\left(x^2-5x+25-x\right)\)
\(=\left(x+5\right)\left(x^2-6x+25\right)\)
Phân tích đa thức thành nhân tử:
a)6x^3y^2.(2-x)+9x^2y^2.(x-2)
b)x^2-4x+4y-y^2
c)81x^2+6yz-9y^2-z^2
a, \(6x^3y^2.\left(2-x\right)+9x^2y^2\left(x-2\right)\)
\(=6x^3y^2.\left(2-x\right)-9x^2y^2\left(2-x\right)\)
\(=y^2.\left(2-x\right)\left(6x^3-9x^2\right)\)
\(=3x^2y^2.\left(2-x\right)\left(2x-3\right)\)
b. \(x^2-4x+4y-y^2\)
\(=\left(x^2-y^2\right)-\left(4x-4y\right)\)
\(=\left(x-y\right)\left(x+y\right)-4\left(x-y\right)\)
\(=\left(x-y\right)\left(x+y-4\right)\)
Phân tích đa thức thành nhân tử bằng kĩ thuật bổ sung hằng đẳng thức a)4x^2+5x-6 b)9x^2-6x-3 c)2x^2-3x-2 d)3x^2+x-2 e)3x^2+10x+3
a: =4x^2+8x-3x-6
=4x(x+2)-3(x+2)
=(x+2)(4x-3)
b: =3(3x^2-2x-1)
=3(3x^2-3x+x-1)
=3(x-1)(3x+1)
c: =2x^2-4x+x-2
=2x(x-2)+(x-2)
=(x-2)(2x+1)
d: =3x^2+3x-2x-2
=3x(x+1)-2(x+1)
=(x+1)(3x-2)
e: =3x^2+9x+x+3
=3x(x+3)+(x+3)
=(x+3)(3x+1)
a) \(4x^2+5x-6\)
\(=4x^2+8x-3x-6\)
\(=\left(4x^2+8x\right)-\left(3x+6\right)\)
\(=4x\left(x+2\right)-3\left(x+2\right)\)
\(=\left(x+2\right)\left(4x-3\right)\)
b) \(9x^2-6x-3\)
\(=3\left(3x^2-2x-1\right)\)
\(=3\left(3x^2-3x+x-1\right)\)
\(=3\left[3x\left(x-1\right)+\left(x-1\right)\right]\)
\(=3\left(x-1\right)\left(3x+1\right)\)
c) \(2x^2-3x-2\)
\(=2x^2-4x+x-2\)
\(=\left(2x^2-4x\right)+\left(x-2\right)\)
\(=2x\left(x-2\right)+\left(x-2\right)\)
\(=\left(2x+1\right)\left(x-2\right)\)
d) \(3x^2+x-2\)
\(=3x^2+3x-2x-2\)
\(=\left(3x^2+3x\right)-\left(2x+2\right)\)
\(=3x\left(x+1\right)-2\left(x+1\right)\)
\(=\left(x+1\right)\left(3x-2\right)\)
e) \(3x^2+10x+3\)
\(=3x^2+9x+x+3\)
\(=3x\left(x+3\right)+\left(x+3\right)\)
\(=\left(x+3\right)\left(3x+1\right)\)
Phân tích các đa thức sau thành nhân tử:
a) x^3-2x^2+5x-4
b) x^3-x^2+x+3
c) 6x^3+x^2+x+1
d) 4x^3+6x^2+4x+1
e) x^6-9x^3+8
Mình đang cần gấp ! Cảm ơn các bạn !
a) x3 -2x2 +5x-4
=x3-x2-x2+x+4x-4
=x2(x-1)-x(x-1)+4(x-1)
=(x2-x+4)(x-1)
b) x3-x2+x+3
=x3+x2-2x2-2x+3x+3
=x2(x+1) -2x(x+1)+3(x+1)
=(x2-2x+3)(x+1)
c) 6x3+x2+x+1
=6x3+ 3x2-2x2-x+2x+1
=6x2(x+\(\frac{1}{2}\)) - 2x(x+\(\frac{1}{2}\)) +2(x+\(\frac{1}{2}\))
=(6x2-2x+2) (x+\(\frac{1}{2}\))
=2( 3x2-x+1) (x+\(\frac{1}{2}\))
d) 4x3 + 6x2+4x+1
= 4x3+2x2+4x2+2x+2x+1
= 4x2(x+\(\frac{1}{2}\))+ 4x(x+\(\frac{1}{2}\))+2(x+\(\frac{1}{2}\))
= 2(2x2 +2x+1)( x+\(\frac{1}{2}\))
e) x6 -9x3+8