phân tích các đa thức sau thành nhân tử
xy +1 -x -y
y +z -1 -yz
ax +ay -bx -by
ax -ay -bx +by
2x^2 -4xy +2y^2 -32
5x^2 -5y^2 -x +y
x^2 +6x +8
x^2 -9x +8
Phân tích đa thức thành nhân tử
x^2-xy+2x-2y
ax+ay-2x-2y
ax^2-3axy+bx-3by
2a^2-5by-5a^2y+2bx
x2-xy+2x-2y
= (x2-xy)+(2x-2y)
= x(x-y)+2(x-y)
= (x-y)(x+2)
ax+ay-2x-2y
= (ax+ay)-(2x+2y)
= a(x+y)-2(x+y)
=(x+y)(a-2)
ax2-3axy+bx-3by
= (ax2+bx)-(3axy+3by)
= x(ax+b)-3y(ax+b)
= (ax+b)(x-3y)
2a2-5by-5a2y+2bx
= (2a2-5a2y)+(2bx-5by)
= a2(2-5y)+b(2x-5y)
x2-xy+2x-2y=(x2-xy)+(2x-2y)=x(x-y)+2(x-y)=(x-y)(x+2)
ax+ay-2x-2y=(ax+ay)-(2x+2y)=a(x+y)-2(x+y)=(x+y)(a-2)
ax2-3axy+bx-3by=(ax2+bx)-(3axy+3by)=x(ax+b)-3y(ax+b)=(ax+b)(x-3y)
Dạng 1: Phân tích đa thức sau thành nhân tử 1) x ^ 2 - 9 2) 5x - 5y + ax - ay 3) x ^ 2 + 6x + 9 4) 10x * (x - y) - 7y * (y - x) 5) 5x - 15y 6) x ^ 2 - 2xy + y ^ 2 - z ^ 2
\(1,=\left(x-3\right)\left(x+3\right)\\ 2,=\left(x-y\right)\left(5+a\right)\\ 3,=\left(x+3\right)^2\\ 4,=\left(x-y\right)\left(10x+7y\right)\\ 5,=5\left(x-3y\right)\\ 6,=\left(x-y\right)^2-z^2=\left(x-y-z\right)\left(x-y+z\right)\)
Phân tích các đa thức sau thành nhân tử:
1) x6 - x4- 9x3 + 9x2
2)(xy + 4)2 - 4(x + y)2
3)(ab - xy)2 - (bx - ay)2
a) x6 - x4 - 9x3 + 9x2
= x4.(x2 - 1) - 9x2(x - 1)
= x4.(x - 1)(x + 1) - 9x2.(x - 1)
= (x - 1).[x4.(x + 1) - 9x2]
= x2.(x - 1).[x2.(x + 1) - 9]
b) (xy + 4)2 - 4(x + y)2
= (xy + 4)2 - [2(x + y)]2
= [xy + 4 - 2(x + y)] . [xy + 4 + 2(x + y)]
c) (ab - xy)2 - (bx - ay)2
= [(ab - xy) - (bx - ay)] . [(ab - xy) + (bx - ay)]
= [ab - xy - bx + ay] . [ab - xy + bx - ay]
= [a.(b + y) - x.(b + y)] . [b(a + x) - y(a + x)]
= (a - x)(b + y).(b - y)(a + x)
phân tích đa thức thành nhân tử
x2-4xy+4y2-2x+4y-35
x2-(a+b)xy+aby2
(xy+ab)2+(ay-bx)2
a: \(x^2-4xy+4y^2-2x+4y-35\)
\(=\left(x^2-4xy+4y^2\right)-\left(2x-4y\right)-35\)
\(=\left(x-2y\right)^2-2\left(x-2y\right)-35\)
\(=\left(x-2y\right)^2-7\left(x-2y\right)+5\left(x-2y\right)-35\)
\(=\left(x-2y\right)\left(x-2y-7\right)+5\left(x-2y-7\right)\)
\(=\left(x-2y-7\right)\left(x-2y+5\right)\)
c: \(\left(xy+ab\right)^2+\left(ay-bx\right)^2\)
\(=x^2y^2+a^2b^2+2xyab+a^2y^2-2aybx+b^2x^2\)
\(=x^2y^2+a^2y^2+a^2b^2+b^2x^2\)
\(=y^2\left(x^2+a^2\right)+b^2\left(a^2+x^2\right)\)
\(=\left(x^2+a^2\right)\left(y^2+b^2\right)\)
Phân tích các đa thức sau thành nhân tử:
a) 2x^2 - 2xy - 5x +5y ; b) 8x^2 + 4xy - 2ax - ay
c) x^3 - 4x^2 + 4x ; d) 2xy - x^2 - y^2 + 16
e) x^2 - y^2 - 2yz - z^2; g) 3a^2 - 6ab + 3b^2 - 12c^2
a) 2x^2 - 2xy - 5x +5y
= (2x^2 - 2xy ) - ( 5x- 5 y)
=2x(x-y) - 5(x-y)
=(x- y). (2x- 5)
b)8x2 +4xy-2ax-ay
=(8x2 +4xy) -(2ax+ay)
=4x(2x+y)-a(2x+y)
=(2x+y).(4x-a)
c)=x(x2 -4x +4)
=x(x-2)2
d)=16- (x2 -2xy +y^2)
=4^2-(x-y)^2
=(4-x+y).(4+x-y)
các câu còn lại tg tự
chúc bn hok tốt
Bài 2 : Phân tích các đa thức sau thành nhân tử :
a) x2 - ( m + n )x + mn
b) ax + by + a - bx - ay - b
\(a,=x^2-mx-nx+mn=x\left(x-m\right)-n\left(x-m\right)=\left(x-n\right)\left(x-m\right)\\ b,=a\left(x-y\right)-b\left(x-y\right)+\left(a-b\right)\\ =\left(x-y\right)\left(a-b\right)+\left(a-b\right)=\left(a-b\right)\left(x-y+1\right)\)
b: \(=a\left(x-y\right)-b\left(x-y\right)+a-b\)
\(=\left(x-y+1\right)\left(a-b\right)\)
a) \(x^2-\left(m+n\right)x+mn=\left(x^2-n\cdot x\right)-\left(m\cdot x-m\cdot n\right)=x\left(x-n\right)-m\left(x-n\right)=\left(x-m\right)\left(x-n\right)\)
b) \(ax+by+a-bx-ay-b\)
\(=\left(ax-ay+a\right)-\left(bx-by+b\right)\)
\(=a\left(x-y+1\right)-b\left(x-y+1\right)\)
\(\left(a-b\right)\left(x-y+1\right)\)
Phân tích đa thức thành nhân tử ; giúp với dg cần gấp
Ax+bx+ay+by
Xy+1-x-y
-2xy+ax-x2-2ay
X2-y2-5x-5y
\(ax+bx+ay+by\)
\(=x\left(a+b\right)+y\left(a+b\right)\)
\(=\left(x+y\right)\left(a+b\right)\)
\(xy+1-x-y\)
\(=x\left(y-1\right)-\left(y-1\right)\)
\(=\left(x-1\right)\left(y-1\right)\)
\(x^2-y^2-5x-5y\)
\(=\left(x+y\right)\left(x-y\right)-5\left(x+y\right)\)
\(=\left(x+y\right)\left(x-y-5\right)\)
Phân tích các đa thức sau thành nhân tử:
a) -16a^4b^6 - 24a^5b^5 - 9a^9b^4
b) ( 3x - 1)^2 - 16
c) ( 3x + 1)^2 - 4( x - 2 )^2
d) ( ax + by) ^2 - ( ay + bx )^2
e) ( 4x^2 - 3x - 18)^2 - ( 4x^2 + 3x )^2
g) 8x^3 - 64
h) 8x^3 - 27
i) x^3 + 6x^2 + 12x + 8
k) x^3 + 3/2x^2 + 3/4x + 1/8
Giúp mình nhé, mình cần gấp lắm
Giúp mk nha
Bài 1 : Phân tích đa thức thành nhân tử
a) x2-6x-y2+9
b) 25-4x2-4xy -y2
c) x2+2xy+y2- xz-yz
d) x2-4xy+4y2-z2+4tz-4t2
Bài 2 : Phân tích đa thức thành nhân tử
a) ax2+cx2-ay+ay2-cy+cy2
b) ax^2+ay^2-bx^2-by^2+b-a
c) ac^2-ad-bc^2+cd+bd-c^3
Bài 3 : Tìm x
a) x(x-5)-4x+20=0
b) x(x+6)-7x-42=0
c) x^3-5x^2+x-5=0
d) x^4-2x^3+10x2-20x=0
Bài 1 :
a ) \(x^2-6x-y^2+9=\left(x^2-6x+9\right)-y^2=\left(x-3\right)^2-y^2=\left(x-3+y\right)\left(x-3-y\right)\)
b) \(25-4x^2-4xy-y^2=5^2-\left(4x^2+4xy+y^2\right)=5^2-\left(2x+y\right)^2=\left(5+2x+y\right)\left(5-2x-y\right)\)
c) \(x^2+2xy+y^2-xz-yz=\left(x+y\right)^2-z.\left(x+y\right)=\left(x+y\right)\left(x+y-z\right)\)
d) \(x^2-4xy+4y^2-z^2+4tz-4t^2=\left(x^2-4xy+4y^2\right)-\left(z^2-4tz+4t^2\right)\)
\(=\left(x-2y\right)^2-\left(z-2t\right)^2=\left(x-2y+z-2t\right).\left(x-2y-z+2t\right)\)
BÀi 2 :
a) \(ax^2+cx^2-ay+ay^2-cy+cy^2=\left(ax^2+cx^2\right)-\left(ay+cy\right)+\left(ay^2+cy^2\right)\)
\(=x^2.\left(a+c\right)-y\left(a+c\right)+y^2.\left(a+c\right)=\left(a+c\right).\left(x^2-y+y^2\right)\)
b) \(ax^2+ay^2-bx^2-by^2+b-a=\left(ax^2-bx^2\right)+\left(ay^2-by^2\right)-\left(a-b\right)\)
\(=x^2.\left(a-b\right)+y^2.\left(a-b\right)-\left(a-b\right)=\left(a-b\right)\left(x^2+y^2-1\right)\)
c) \(ac^2-ad-bc^2+cd+bd-c^3=\left(ac^2-ad\right)+\left(cd+bd\right)-\left(bc^2+c^3\right)\)
\(=-a.\left(d-c^2\right)+d.\left(b+c\right)-c^2.\left(b+c\right)=\left(b+c\right).\left(d-c^2\right)-a\left(d-c^2\right)\)
\(=\left(b+c-a\right)\left(d-c^2\right)\)
BÀi 3 :
a) \(x.\left(x-5\right)-4x+20=0\) \(\Leftrightarrow x\left(x-5\right)-4\left(x-5\right)=0\) \(\Leftrightarrow\left(x-5\right)\left(x-4\right)=0\)
\(\Leftrightarrow\hept{\begin{cases}x-5=0\\x-4=0\end{cases}\Leftrightarrow\hept{\begin{cases}x=5\\x=4\end{cases}}}\)
b) \(x.\left(x+6\right)-7x-42=0\)\(\Leftrightarrow x.\left(x+6\right)-7.\left(x+6\right)=0\) \(\Leftrightarrow\left(x+6\right)\left(x-7\right)=0\)
\(\Leftrightarrow\hept{\begin{cases}x+6=0\\x-7=0\end{cases}\Leftrightarrow\hept{\begin{cases}x=-6\\x=7\end{cases}}}\)
c) \(x^3-5x^2+x-5=0\) \(\Leftrightarrow x^2.\left(x-5\right)+\left(x-5\right)=0\) \(\Leftrightarrow\left(x-5\right)\left(x^2+1\right)\)
\(\Leftrightarrow\hept{\begin{cases}x^2+1=0\\x-5=0\end{cases}\Leftrightarrow\hept{\begin{cases}x^2=-1\left(KTM\right)\\x=5\end{cases}}}\)
d) \(x^4-2x^3+10x^2-20x=0\) \(\Leftrightarrow x.\left(x^3-2x^2+10x-20\right)=0\)\(\Leftrightarrow x.\left[x^2.\left(x-2\right)+10.\left(x-2\right)\right]=0\) \(\Leftrightarrow x.\left(x-2\right)\left(x^2+10=0\right)\)
\(\Leftrightarrow\hept{\begin{cases}x=0\\x-2=0\\x^2+10=0\end{cases}\Leftrightarrow\hept{\begin{cases}x=0\\x=2\\x^2=-10\left(KTM\right)\end{cases}}}\)