Phân tích đa thức thành phân tử:
a)A=5(x-y)+ax-ay
b)B=a(x+y)-4x-4y
c)C=xz+yz-5(x+y)
d)D=a(x-y)+bx-by
e)E=x(x+y)-5x-5y
f)F=x2-x-y2-y
g)G=x2-xy+x-y
Bài 1: Phân tích các đa thức sau thành nhân tử
a. 1 - 4x2
b. 8 - 27x3
c. 27 + 27x + 9x 2 + x3
d. 2x3 + 4x2 + 2x
e. x2 - 5x - y2 + 5y
f. x2 - 6x + 9 - y2
g. 10x (x - y) - 6y(y - x)
h. x2 - 4x - 5
i. x4 - y4
Bài 2: Tìm x, biết
a. 5(x - 2) = x - 2
b. 3(x - 5) = 5 - x
c. (x +2)2 - (x+ 2) (x - 2) = 0
Bài 3: Tìm giá trị nhỏ nhất của biểu thức
a. A = x2 - 6x + 11
b. B = 4x2 - 20x + 101
c. C = -x2 - 4xy + 5y2 + 10x - 22y + 28
a.
\(1-4x^2=\left(1-2x\right)\left(1+2x\right)\)
b.
\(8-27x^3=\left(2\right)^3-\left(3x\right)^3=\left(2-3x\right)\left(4+6x+9x^2\right)\)
c.
\(27+27x+9x^2+x^3=x^3+3.x^2.3+3.3^2.x+3^3\)
\(=\left(x+3\right)^3\)
d.
\(2x^3+4x^2+2x=2x\left(x^2+2x+1\right)=2x\left(x+1\right)^2\)
e.
\(x^2-y^2-5x+5y=\left(x-y\right)\left(x+y\right)-5\left(x-y\right)\)
\(=\left(x-y\right)\left(x+y-5\right)\)
f.
\(x^2-6x+9-y^2=\left(x-3\right)^2-y^2=\left(x-3-y\right)\left(x-3+y\right)\)
g. 10x(x-y)-6y(y-x)
=10x(x-y)+6y(x-y)
=(x-y)(10x+6y)
h.x2-4x-5
=(x-5)(x+1)
i.x4-y4 = (x2-y2)(x2+y2)
B2.
a.5(x-2)=x-2
⇔5(x-2)-(x-2)=0
⇔4(x-2)=0
⇔x=2
b.3(x-5)=5-x
⇔3(x-5)+(x-5)=0
⇔4(x-5)=0
⇔x=5
c.(x+2)2-(x+2)(x-2)=0
⇔(x+2)[(x+2)-(x-2)]=0
⇔4(x+2)=0
⇔x=-2
Phân tích đa thức thành nhân tử:
a) m x 2 + my - n x 2 - ny; b) mz - 2z - m 2 + 2m;
c) x 2 y 2 + y 3 + z x 2 + yz; d) 2x2 + 4mx + x + 2m.
e) x 4 - 9 x 3 + x 2 - 9x; g) 3 x 2 -2 ( x - y ) 2 - 3 y 2 .
h*) xy(x + y) + yz (y + z) + xz(x + z) + 2xyz.
Phân tích các đa thức sau thành nhân tử:
a) 8 x 3 - 2x; b) 5x - 25 x 2 + 10 x 3 9 ;
c) -5 x 3 (x + 1) + x + 1; d) x 3 27 + x 6 729 − x 9 ;
e) x ( y - x ) 2 - x 2 + 2xy - y 2 ; g) x ( x – y ) 2 - y ( x – y ) 2 + x y 2 - x 2 y.
nhờ giải giupws em với a
1. Phân tích các đa thức sau thành nhân tử:
a) 5x2 – 10xy
b) 3x(x – y) – 6(x – y)
c) 2x(x – y) – 4y(y – x)
d) 9x2 – 9y2
e) x2 – xy – x + y
f) xy – xz – y + z
2. Phân tích các đa thức sau thành nhân tử:
a)a2 – 4b2 b) x2 – y2 + 6y - 9
c) (2a + b)2 – a2 d) 16(x – 1)2 – 25(x + y)2
e)x2 + 10x + 25 f) 25x2 – 20xy + 4y2
g)9x4 + 24x2 + 16 h) x3 – 125
i)x6 – 1 k) x3 + 15x2 + 75x + 125
3. Tìm x biết :
a) 3x2 + 8x = 0 b) 9x2 – 25 = 0 c) x3 – 16x = 0 d) x3 + x = 0.
4. Chứng minh rằng với mọi số nguyên a thì: a3 – a chia hết cho 6
Bài `1`
\(a,5x^2-10xy=5x\left(x-2y\right)\\ b,3x\left(x-y\right)-6\left(x-y\right)=\left(x-y\right)\left(3x-6\right)\\ =3\left(x-y\right)\left(x-2\right)\\ c,2x\left(x-y\right)-4y\left(y-x\right)=2x\left(x-y\right)+4y\left(x-y\right)\\ =\left(x-y\right)\left(2x+4y\right)=2\left(x-y\right)\left(x+2y\right)\\ d,9x^2-9y^2=\left(3x\right)^2-\left(3y\right)^2=\left(3x-3y\right)\left(3x+3y\right)\\ f,xy-xz-y+z=\left(xy-xz\right)-\left(y-z\right)\\ =x\left(y-z\right)-\left(y-z\right)=\left(y-z\right)\left(x-1\right)\)
Bài `3`
\(a,3x^2+8x=0\\ \Leftrightarrow x\left(3x+8\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}x=0\\3x+8=0\end{matrix}\right.\\ \Leftrightarrow\left[{}\begin{matrix}x=0\\3x=-8\end{matrix}\right.\\ \Leftrightarrow\left[{}\begin{matrix}x=0\\x=-\dfrac{8}{3}\end{matrix}\right.\)
\(b,9x^2-25=0\\ \Leftrightarrow\left(3x\right)^2-5^2=0\\ \Leftrightarrow\left(3x-5\right)\left(3x+5\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}3x-5=0\\3x+5=0\end{matrix}\right.\\ \Leftrightarrow\left[{}\begin{matrix}3x=5\\3x=-5\end{matrix}\right.\\ \Leftrightarrow\left[{}\begin{matrix}x=\dfrac{5}{3}\\x=-\dfrac{5}{3}\end{matrix}\right.\)
\(c,x^3-16x=0\\ \Leftrightarrow x\left(x^2-16\right)=0\\ \Leftrightarrow x\left(x-4\right)\left(x+4\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}x=0\\x-4=0\\x+4=0\end{matrix}\right.\\ \Leftrightarrow\left[{}\begin{matrix}x=0\\x=4\\x=-4\end{matrix}\right.\)
\(d,x^3+x=0\\ \Leftrightarrow x\left(x^2+1\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}x^2+1\in\varnothing\\x=0\end{matrix}\right.\Rightarrow x=0\)
1. Phân tích các đa thức sau thành nhân tử:
a) 5x2 – 10xy
b) 3x(x – y) – 6(x – y)
c) 2x(x – y) – 4y(y – x)
d) 9x2 – 9y2
e) x2 – xy – x + y
f) xy – xz – y + z
Lời giải:
a. $5x^2-10xy=5x(x-2y)$
b. $3x(x-y)-6(x-y)=(x-y)(3x-6)=3(x-y)(x-2)$
c. $2x(x-y)-4y(y-x)=2x(x-y)+4y(x-y)=(x-y)(2x+4y)=2(x-y)(x+2y)$
d. $9x^2-9y^2=9(x^2-y^2)=9(x-y)(x+y)$
e. $x^2-xy-x+y=(x^2-xy)-(x-y)=x(x-y)-(x-y)=(x-y)(x-1)$
f. $xy-xz-y+z=(xy-y)-(xz-z)=y(x-1)-z(x-1)=(x-1)(y-z)$
Phân tích đa thức thành nhân tử
a)A=xy+y-2x-2
b)B=x2-3x+xy-3y
c)C=3x2-3xy-5x+5y
d)D=xy+1+x+y
e)E=ax-bx+ab-x2
f)F=x2+ab+ax+bx
g)G=a3-a2x-ay+xy
h)H=2xy+3z+6y+xz
A = xy + y - 2x - 2
= y( x + 1 ) - 2( x + 1 )
= ( x + 1 )( y - 2 )
B = x2 - 3x + xy - 3y
= x( x - 3 ) + y( x - 3 )
= ( x - 3 )( x + y )
C = 3x2 - 3xy - 5x + 5y
= 3x( x - y ) - 5( x - y )
= ( x - y )( 3x - 5 )
D = xy + 1 + x + y
= y( x + 1 ) + ( x + 1 )
= ( x + 1 )( y + 1 )
E = ax - bx + ab - x2
= ( ax - x2 ) + ( ab - bx )
= x( a - x ) + b( a - x )
= ( a - x )( x + b )
F = x2 + ab + ax + bx
= ( ax + x2 ) + ( ab + bx )
= x( a + x ) + b( a + x )
= ( a + x )( x + b )
G = a3 - a2x - ay + xy
= a2( a - x ) - y( a - x )
= ( a - x )( a2 - y )
Bonus : = ( a - x )[ a2 - ( √y )2 ]
= ( a - x )( a - √y )( a + √y )
H = 2xy + 3z + 6y + xz
= ( 6y + 2xy ) + ( 3z + xz )
= 2y( 3 + x ) + z( 3 + x )
= ( 3 + x )( 2y + z )
A = xy + y - 2x - 2 = y(x + 1) - 2(x + 1) = (y - 2)(x + !1
B = x2 - 3x + xy - 3y = x(x - 3) + y(x - 3) = (x + y)(x - 3)
C = 3x2 - 3xy - 5x + 5y = 3x(x - y) - 5(x - y) = (3x - 5)(x - y)
D = xy + 1 + x + y = xy + x + y + 1 = x(y + 1) + (y + 1) = (x + 1)(y + 1)
E = ax - bx + ab - x2 = ax - x2 + ab - bx = a(a - x) - b(a - x) = (a - b)(a - x)
F = x2 + ab + ax + bx = ab + ax + bx + x2 = a(b + x) + x(b + x) = (a + x)(b + x)
G = a3 - a2x - ay + xy = a2(a - x) - y(a - x) = (a2 - y)(a - x)
H = 2xy + 3z + 6y + xz = 2xy + 6y + 3z + xz = 2y(x + 3) + z(x + 3) = (2y + z)(x + 3)
🍀Trần Nhật Quỳnh🍀 y không dương nên không thể cho vào căn nhé
Phân tích các đa thức sau thành nhân tử:
a) x2 - 9 - x2 (x2 - 9) d) x2 + 5x + 6 h) a2 + b2 + 2a – 2b – 2ab
b) x2(x-y) + y2(y-x) e) 3x2 – 4x – 4 i) (x + 1)2 – 2(x + 1)(y – 3) + (y – 3)2
c) x3+27+(x+3)(x-9) g) x4 + 64y4 k) x2(x + 1) – 2x(x + 1) + x + 1
Mình đang cần gấp ạ
a: \(x^2-9-x^2\left(x^2-9\right)\)
\(=\left(x^2-9\right)-x^2\left(x^2-9\right)\)
\(=\left(x^2-9\right)\left(1-x^2\right)\)
\(=\left(1-x\right)\left(1+x\right)\left(x-3\right)\left(x+3\right)\)
b: \(x^2\left(x-y\right)+y^2\left(y-x\right)\)
\(=x^2\left(x-y\right)-y^2\left(x-y\right)\)
\(=\left(x-y\right)\left(x^2-y^2\right)\)
\(=\left(x-y\right)\left(x-y\right)\left(x+y\right)=\left(x-y\right)^2\cdot\left(x+y\right)\)
c: \(x^3+27+\left(x+3\right)\left(x-9\right)\)
\(=\left(x+3\right)\left(x^2-3x+9\right)+\left(x+3\right)\left(x-9\right)\)
\(=\left(x+3\right)\left(x^2-3x+9+x-9\right)\)
\(=\left(x+3\right)\left(x^2-2x\right)=x\left(x-2\right)\left(x+3\right)\)
d: \(x^2+5x+6\)
\(=x^2+2x+3x+6\)
\(=x\left(x+2\right)+3\left(x+2\right)=\left(x+2\right)\left(x+3\right)\)
e: \(3x^2-4x-4\)
\(=3x^2-6x+2x-4\)
\(=3x\left(x-2\right)+2\left(x-2\right)\)
\(=\left(x-2\right)\left(3x+2\right)\)
g: \(x^4+64y^4\)
\(=x^4+16x^2y^2+64y^4-16x^2y^2\)
\(=\left(x^2+8y^2\right)^2-\left(4xy\right)^2\)
\(=\left(x^2+8y^2-4xy\right)\left(x^2+8y^2+4xy\right)\)
h: \(a^2+b^2+2a-2b-2ab\)
\(=a^2-2ab+b^2+2a-2b\)
\(=\left(a-b\right)^2+2\left(a-b\right)=\left(a-b\right)\left(a-b+2\right)\)
i: \(\left(x+1\right)^2-2\left(x+1\right)\left(y-3\right)+\left(y-3\right)^2\)
\(=\left(x+1-y+3\right)^2\)
\(=\left(x-y+4\right)^2\)
k: \(x^2\left(x+1\right)-2x\left(x+1\right)+\left(x+1\right)\)
\(=\left(x+1\right)\left(x^2-2x+1\right)\)
\(=\left(x+1\right)\left(x-1\right)^2\)
Phân tích các đa thức sau thành nhân tử:
a) 3x-6
b) x2-4x+4
c) x2-y2+5x-5y
d) 8(x+y+z)3-(x+y)3-(y+z)3-(y+z)3-(z+x)3
Do câu d mình ko biết làm bởi v mình không làm được
: Phân tích đa thức thành nhân tử.
a) 5x2y - 10xy2 b) 3(x + 3) + x2 - 9 c) x2 – y 2 + xz - yz
d/ 14x2y – 21xy2 + 28x2y2 e/ x(x + y) – 5x – 5y.
f/ 10x(x – y) – 8(y – x). g/ (3x + 1)2 – (x + 1)2 h) x2-5x+6
a,=5xy(x-2y)
b,=3(x+3)+(x-3)(x+3)
=(x+3)+x
c=xy(x-y)+z(x-y)
=(x-y)(xy+z)
d=7xy(2x-3y+4xy)
e,=x(x+y)-5(x+y)
= (x+y)(x-5)
f, =10x(x-y)+8(x-y)
=(x-y)(10x+8)
g,=(3x+1-x+1)(3x+1+x+1)
=2x(4x+2)
h,=x^2-3x-2x+6
= x(x-3)-2(x-3)
=(x-3)(x-2)