Phân tích thành nhân tử:
a, 3x4+2x3-8x2-2x+5
b, 2x4-9x3+4x2+21x-18
phân tích đa thức thành nhân thức
a, x2 - 2x + x - 2
b, 8x2 + 4x + 4
c, x3 + 4x2 + 2x4
\(a,=x\left(x-2\right)+\left(x-2\right)=\left(x+1\right)\left(x-2\right)\\ b,=4\left(2x^2+x+1\right)\\ c,=x^2\left(2x^2+x+4\right)\)
1. Phân tích thành nhân tử
a) x2 + 7x + 10; b) x2 – 21x + 110; c) 3x2 + 12x + 9; d) 2ax2 - 16ax + 30a.
2. Phân tích thành nhân tử
a) x2 + x – 6; b) x2 – 2x – 15; c) 4x2 - 12x - 160; d) 5x2y - 10xy - 15y.
3. Phân tích thành nhân tử
a) x2 – xy – 20y2 ; b) 3x4 + 6x2y2 – 45y4 ; c) 2bx2 – 4bxy - 70y2
4. Giải phương trình
a) x2 + x = 72; b) 3x2 – 6x = 24 c) 5x3 – 10x2 = 120x.
5. Phân tích thành nhân tử
a) 3x2 -11x + 6; b) 8x2 + 10x – 3 ; c) 8x2 -2x -1 .
Phân tích các đa thức sau thành nhân tử:
a) 4x2- 4xy+ y2
b) 9x3-9x2y - 4x + 4y
c) x2+ 2 + 3(x2-2)
\(a,=\left(2x-y\right)^2\\ b,=9x^2\left(x-y\right)-4\left(x-y\right)=\left(3x-2\right)\left(3x+2\right)\left(x-y\right)\\ c,=x^2+2+3x^2-6=4x^2-4=4\left(x-1\right)\left(x+1\right)\)
Bài 4. Phân tích các đa thức sau thành nhân tử:
a) 36x3 y3 - 42x2 y2
b) 3x4 y2 + 15x2 y -18xy
c) ax - bx + ab - x2
d) 3(2x -1) - 4x2 + 4x -1
a) \(=6x^2y^2\left(6xy-7\right)\)
b) \(=3xy\left(x^3y+5x-6\right)\)
c) \(=\left(ax+ab\right)-\left(bx+x^2\right)=a\left(b+x\right)-x\left(b+x\right)=\left(a-x\right)\left(b+x\right)\)
d) \(=3\left(2x-1\right)-\left(2x-1\right)^2=\left(2x-1\right)\left(3-2x+1\right)=\left(2x-1\right)\left(4-2x\right)=2\left(2x-1\right)\left(2-x\right)\)
\(a,=6x^2y^2\left(6xy-7\right)\\ b,=3xy\left(x^3y+5x-6\right)\\ c,=x\left(a-x\right)-b\left(a-x\right)=\left(x-b\right)\left(a-x\right)\\ d,=3\left(2x-1\right)-\left(2x-1\right)^2=\left(2x-1\right)\left(3-2x+1\right)=2\left(2-x\right)\left(2x-1\right)\)
Phân tích đa thức thành nhân tử:
a)x4 - 4x2 - 8x2+ 8x
b)x2 - 1 - xy + y
c)(x-1)(x-2)(x-3) + (x-1)(x-2)(x-1)
a: \(x^4-4x^3-8x^2+8x\)
\(=x\left(x^3-4x^2-8x+8\right)\)
\(=x\left[\left(x+2\right)\left(x^2-2x+4\right)-4x\left(x+2\right)\right]\)
\(=x\left(x+2\right)\left(x^2-6x+4\right)\)
b: \(x^2-1-xy+y\)
\(=\left(x-1\right)\left(x+1\right)-y\left(x-1\right)\)
\(=\left(x-1\right)\left(x-y+1\right)\)
c: Ta có: \(\left(x-1\right)\left(x-2\right)\left(x-3\right)+\left(x-1\right)^2\cdot\left(x-2\right)\)
\(=\left(x-1\right)\cdot\left(x-2\right)\cdot\left(x-3-x-1\right)\)
\(=2\cdot\left(x-1\right)\cdot\left(x-2\right)^2\)
Phân tích các đa thức sau thành nhân tử:
a) 4x2-4x+1
b)16y3-2x3-6x(x+1)-2
c)x2-6xy-25z2+9y2
\(a,4x^2-4x+1\\ =\left(2x\right)^2-2.2x+1^2=\left(2x-1\right)^2\\ c,x^2-6xy-25z^2+9y^2\\ =\left(x^2-2.x.3y+9y^2\right)-\left(5z\right)^2\\ =\left(x-3y\right)^2-\left(5z\right)^2\\ =\left(x-3y-5z\right)\left(x-3y+5z\right)\)
Xem lại đề ý b
Phân tích các đa thức sau thành nhân tử:
a/ 2x3 + 3x2 + 2x +3 b/ x2 – x – 12 c/ 4x2 –( x2 + 1)2
d/ 4xy2 – 12x2y + 8xy e/ x2 + x – 6 f/ x3 + 2x2y + xy2 – 4xz2
g/ x3 – 2x2y + xy2 – 25x h/ x2 – 2x – 3 i/ x3 – 3x2 – 9x + 27
a: \(=x^2\left(2x+3\right)+\left(2x+3\right)\)
\(=\left(2x+3\right)\left(x^2+1\right)\)
b: \(=\left(x-4\right)\left(x+3\right)\)
e: =(x+3)(x-2)
a) \(=x^2\left(2x+3\right)+\left(2x+3\right)=\left(2x+3\right)\left(x^2+1\right)\)
b) \(=x\left(x-4\right)+3\left(x-4\right)=\left(x-4\right)\left(x+3\right)\)
c) \(=\left(2x\right)^2-\left(x^2+1\right)^2=\left(x^2-2x+1\right)\left(x^2+2x+1\right)=\left(x-1\right)^2\left(x+1\right)^2\)
d) \(=4xy\left(y-3x+2\right)\)
e) \(=x\left(x-2\right)+3\left(x-2\right)=\left(x-2\right)\left(x+3\right)\)
f) \(=x\left(x^2+2xy+y^2-4z^2\right)=x\left[\left(x+y\right)^2-4z^2\right]=x\left(x+y-2z\right)\left(x+y+2z\right)\)
g) \(=x\left(x^2-2xy+y^2-25\right)=x\left[\left(x-y\right)^2-25\right]=x\left(x-y-5\right)\left(x-y+5\right)\)
h) \(=x\left(x+1\right)-3\left(x+1\right)=\left(x+1\right)\left(x-3\right)\)
i) \(=x^2\left(x-3\right)-9\left(x-3\right)=\left(x-3\right)\left(x^2-9\right)=\left(x-3\right)^2\left(x+3\right)\)
Phân tích đa thức thành nhân tử:
a) ( x - 1 )x + ( x - 1 )y
b) 5x3 + 15xy
c) 6xy2 - 8x2yy
d) 2x3 + 4x2 - 6x
e) 5( x - 3 ) - 20( 3 - x )
\(a)(x-1)x+(x-1)y\)
\(=(x-1)(x+y)\)
\(b)5x^3+15xy\)
\(=5x(x^2+3y)\)
\(c)6xy^2-8x^2y\)
\(=2xy(3y-4x)\)
\(d)2x^3+4x^2-6x\)
\(=2x(x^2+2x-3)\)
\(e)5(x-3)-20(3-x)\)
\(=5(x-3)+20(x-3)\)
\(=(x-3)(5+20)\)
\(=25(x-3)\)
a: =(x-1)(x+y)
b: =5x(x^2+3y)
c: 6xy^2-8x^2y=2xy(3y-4x)
d: =2x(x^2+2x-3)
=2x(x+3)(x-1)
e: =25(x-3)
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)`
Phân tích các đa thức sau thành nhân tử:
a/ y2 - 2y b/ 3x4 – 6x3 + 3x2
c/ 27x2 ( y – 1) – 9x3 ( 1 - y) d/y3 – 2y2 + y
e/ x3 + 6x2 + 9x f/ x3 – 2x2y + xy2
g/ x( 2- x) – x + 2 h/ 3x ( x – 1) + 6( 1 – x)
\(a,=y\left(y-2\right)\\ b,=3x\left(x^2-2x+1\right)=3x\left(x-1\right)^2\\ c,=\left(y-1\right)\left(27x^2+9x^3\right)=9x^2\left(x+3\right)\left(y-1\right)\\ d,=y\left(y^2-2y+1\right)=y\left(y-1\right)^2\\ e,=x\left(x^2+6x+9\right)=x\left(x+3\right)^2\\ f,=x\left(x^2-2xy+y^2\right)=x\left(x-y\right)^2\\ g,=\left(2-x\right)\left(x+1\right)\\ h,=\left(x-1\right)\left(3x-6\right)=3\left(x-1\right)\left(x-2\right)\)
a: =y(y-2)
b: \(=3x^2\left(x^2-2x+1\right)=3x^2\left(x-1\right)^2\)
d: \(=y\left(y^2-2y+1\right)=y\left(y-1\right)^2\)