Phân Tích các đa thức sau thành nhân tử
a) x2-2x-3
b) a4+5a3+15a-9
Phân tích đa thức thành nhân tử
a) \(15a^2b^3+5a^3b^2\)
b) \(x^2-2x+x-y^2\)
\(a,15a^2b^3+5a^3b^2=5a^2b^2\left(3b+a\right)\\ b,x^2-2x+1-y^2=\left(x-1\right)^2-y^2=\left(x-y-1\right)\left(x+y-1\right)\)
a) 15a2b3+5a3b2=5a2b2(3b+a)
b) x2-2x+x-y2=( x2-y2)-(2x+x)
=(x-y)(x+y)-x(2-1)
=(x-y)(x+y)-x3
PHÂN TÍCH ĐA THỨC THÀNH NHÂN TỬ
a, 3x(2x - y) + 5y(y - 2x)
b, (x - 5)2 - 9(x + y)2
c, y2 + 2yz + z2 - xy - xz
d, x2 - 9x2y2 + y2 + 2xy
e, x2 - 10x + 24
g, 6x2 + 7x - 5
h, x2 + 4xy - 12y2
k, a4 + 3a2 + 4
a) \(3x\left(2x-y\right)+5y\left(y-2x\right)\)
\(=3x\left(2x-y\right)-5y\left(2x-y\right)\)
\(=\left(3x-5y\right)\left(2x-y\right)\)
b) \(\left(x-5\right)^2-9\left(x+y\right)^2\)
\(=\left(x-5\right)^2-3^2\left(x+y\right)^2\)
\(=\left(x-5\right)^2-\left(3x+3y\right)^2\)
\(=\left(x-5+3x+3y\right)\left(x-5-3x-3y\right)\)
\(=\left(4x+3y-5\right)\left(-2x-3y-5\right)\)
a: \(3x\left(2x-y\right)+5y\left(y-2x\right)=\left(2x-y\right)\left(3x-5y\right)\)
e: \(x^2-10x+24=\left(x-4\right)\left(x-6\right)\)
g) \(6x^2+7x-5\)
=\(6x^2+10x-3x-5\)
=\(\left(6x^2+10x\right)-\left(3x+5\right)\)
=\(2x\left(3x+5\right)-\left(3x+5\right)\)
=\(\left(2x-1\right)\left(3x+5\right)\)
1.Phân tích đa thức sau thành nhân tử
a,x2+4x-3
b,16x-5x2-3
c,2x2+3x-5
d,2x2+3x-5
b) \(16x-5x^2-3=5x\left(3-x\right)-\left(3-x\right)=\left(3-x\right)\left(5x-1\right)\)
c) \(2x^2+3x-5=2x\left(x-1\right)+5\left(x-1\right)=\left(x-1\right)\left(2x+5\right)\)
d) \(2x^2+3x-5=2x\left(x-1\right)+5\left(x-1\right)=\left(x-1\right)\left(2x+5\right)\)
Bài 1:phân tích đa thức thành nhân tử
a)x2-2x-4y2-4y e)x4+2x3+2x2+2x+1
b)x3+2x2+2x+1 f)x5+x4+x3+x2+x+1
c)x3-4x2+12x-27
d)a6-a4+2a3+2a2
Làm chi tiết giúp mình với ạ, cảm ơn
a) \(x^2-2x-4y^2-4y=\left(x^2-4y^2\right)-\left(2x+4y\right)=\left(x-2y\right)\left(x+2y\right)-2\left(x+2y\right)=\left(x+2y\right)\left(x-2y-2\right)\)
b) \(x^3+2x^2+2x+1=\left(x+1\right)\left(x^2-x+1\right)+2x\left(x+1\right)=\left(x+1\right)\left(x^2-x+1+2x\right)=\left(x+1\right)\left(x^2+x+1\right)\)
c) \(x^3-4x^2+12x-27=x^3-3x^2-x^2+3x+9x-27=x^2\left(x-3\right)-x\left(x-3\right)+9\left(x-3\right)=\left(x-3\right)\left(x^2-x+9\right)\)
d) \(a^6-a^4+2a^3+2a^2=a^2\left(a^4-a^2+2a+2\right)=a^2\left[a^2\left(a-1\right)\left(a+1\right)+2\left(a+1\right)\right]=a^2\left(a+1\right)\left(a^3-a^2+2\right)=a^2\left(a+1\right)\left[a^3+a^2-2a^2+2\right]=a^2\left(a+1\right)\left[a^2\left(a+1\right)-2\left(a-1\right)\left(a+1\right)\right]=a^2\left(a+1\right)^2\left(a^2-2a+2\right)\)
a) Ta có: \(x^2-2x-4y^2-4y\)
\(=\left(x^2-4y^2\right)-\left(2x+4y\right)\)
\(=\left(x-2y\right)\left(x+2y\right)-2\left(x+2y\right)\)
\(=\left(x+2y\right)\left(x-2y-2\right)\)
b) Ta có: \(x^3+2x^2+2x+1\)
\(=\left(x^3+1\right)+2x\left(x+1\right)\)
\(=\left(x+1\right)\left(x^2-x+1\right)+2x\left(x+1\right)\)
\(=\left(x+1\right)\left(x^2+x+1\right)\)
d) Ta có: \(a^6-a^4+2a^3+2a^2\)
\(=a^2\left(a^4-a^2+2a+2\right)\)
\(=a^2\left[a^2\left(a^2-1\right)+\left(2a+2\right)\right]\)
\(=a^2\left[a^2\left(a-1\right)\left(a+1\right)+2\left(a+1\right)\right]\)
\(=a^2\cdot\left(a+1\right)\left(a^3-a+2\right)\)
c) Ta có: \(x^3-4x^2+12x-27\)
\(=\left(x^3-27\right)-\left(4x^2-12x\right)\)
\(=\left(x-3\right)\left(x^2+3x+9\right)-4x\left(x-3\right)\)
\(=\left(x-3\right)\left(x^2-x+9\right)\)
Bài 5. Phân tích các đa thức thành nhân tử
a) (x2-4x)2-8(x2-4x)+15 b) (x2+2x)2+9x2+18x+20
c) ( x+1)(x+2)(x+3)(x+4)-24 d) (x-y+5)2-2(x-y+5)+1
Bài 6. Phân tích các đa thức thành nhân tử
a) x2y+x2-y-1 b) (x2+x)2+4(x2+x)-12
c) (6x+5)2(3x+2)(x+1)-6
Bài 1: Phân tích các đa thức sau thành nhân tử
a) 2x2 - xy + 2x - y
b) ac + bc - 2 (a + b)
c) x2 + 4xy + 2x + 8y
d) x2 + 2xy + 3x + 6y
\(a,=x\left(2x-y\right)+\left(2x-y\right)=\left(x+1\right)\left(2x-y\right)\\ b,=\left(a+b\right)\left(c-2\right)\\ c,=x\left(x+4y\right)+2\left(x+4y\right)=\left(x+2\right)\left(x+4y\right)\\ d,=x\left(x+2y\right)+3\left(x+2y\right)=\left(x+3\right)\left(x+2y\right)\)
Phân tích đa thức sau thành nhân tử:
a) 14x2y - 21xy2 + 28x2y2
b) 3x2- 5x - 3xy + 5y
c) 5a3 - 20a
d) 2x+ 2y + x2+ 2xy + y2
a) \(14x^2y-21xy^2+28x^2y^2\)
\(=7xy\left(2x-3y+4xy\right)\)
b) \(3x^2-5x-3xy+5y\)
\(=\left(3x^2-3xy\right)-\left(5x-5y\right)\)
\(=3x\left(x-y\right)-5\left(x-y\right)\)
\(=\left(x-y\right)\left(3x-5\right)\)
c) \(5a^3-20a\)
\(=5a\left(a^2-4\right)\)
\(=5a\left(a-2\right)\left(a+2\right)\)
d) \(2x+2y+x^2+2xy+y^2\)
\(=2\left(x+y\right)\left(x+y\right)^2\)
= \(=\left(x+y\right)\left(2+x+y\right)\)
Phân tích đa thức thành nhân tử
a) a4+a3+a2+a
b) 3xy2+5y-3xy+(-5x)
c) xy-z+y-xz
d) x2-bx+ax-ab
Lời giải:
a. $a^4+a^3+a^2+a=(a^4+a^3)+(a^2+a)$
$=a^3(a+1)+a(a+1)=(a+1)(a^3+a)=a(a+1)(a^2+1)$
b. $3xy^2+5y-3x^2y+(-5x)=(3xy^2-3x^2y)+(5y-5x)$
$=3xy(y-x)+5(y-x)=(y-x)(3xy+5)$
c. $xy-z+y-xz=(xy+y)-(z+xz)=y(x+1)-z(x+1)=(x+1)(y-z)$
d.
$x^2-bx+ax-ab=(a^2+ax)-(bx+ab)=a(a+x)-b(a+x)=(a+x)(a-b)$
phân tích đa thức thành nhân tử
a) (x+y)3+(x-y)3
b) x3-y3+2x2-2y2
c) x3+1-x2-x
Phân tích các đa thức sau thành nhân tử
a) 5a - 20b
b) y2 + 2y - x2 + 1
\(a,=5\left(a-4b\right)\\ b,=\left(y+1\right)^2-x^2=\left(y+1-x\right)\left(x+y+1\right)\)
a) 5a - 20b
= 5 ( a - 4b )
b) y^2 + 2y - x^2 + 1
= ( y^2 + 2y + 1 ) - x^2
= ( y + 1 )^2 - x^2
= ( y + 1 + x ) ( y + 1 - x )