Phân tích thành nhân tử :
a) \(x^2-9\)
b) \(4x^2-25\)
c) \(x^6-y^6\)
phân tích thành nhân tử
a) x^2 - 9
b) 4x^2 - 25
c) x^6 - y^6
a, x^2-9=(x-3)(x+3)
b,4x^2-25=(2x-5)(2x+5)
c,x^6-y^6=(x^3-y^3)(x^3+y^3)
1) phân tích đa thức thành nhân tử
a) 4x^4 - 32x^2 + 1
b) x^6 + 27
c) 3(x^4 + x^2 + 1) - (x^2 - x + 1)
d) (2x^2 -4)^2 + 9
2) phân tích đa thức thành nhân tử
a) 4x^4 + 1
b) 64x^4 + y^4
c) x^8 + x^4 + 1
phân tích các đa thức sau thành nhân tử:
a) 5x(x-2y0 + 2( 2y - x ) ^2
b) 7x( y - 4 ) ^2 - ( 4 - y )^3
c) ( 4x - 8 )(x^2 +6 ) - ( 4x -8 )( x+7) +9 ( 8-4x )
Ta có : 5x(x - 2y) + 2(2y - x)2
= 5x(x - 2y) + 2(x - 2y)2 (vì (2y - x)2 = (x - 2y)2 )
= (x - 2y)[5x + 2(x - 2y)]
= (x - 2y)(5x + 2x - 4y)
= (x - 2y)(7x - 4y)
b) 7x(y - 4)2 - (4 - y)3
= 7x(y - 4)2 - (4 - y)2(4 - y)
= 7x(y - 4)2 - (y - 4)2(4 - y)
= (y - 4)2(7x - 4 + y)
c) (4x - 8)(x2 + 6) - (4x - 8)(x + 7) + 9(8 - 4x)
= (4x - 8)(x2 + 6) - (4x - 8)(x + 7) - 9(4x - 8)
= (4x - 8)(x2 + 6 - x - 7 - 9)
= 2(x - 4)(x2 - x - 10)
phân tích các đa thức sau thành nhân tử
a)7x(y-4)^2-(4-y)^3
b)(4x-8)(x^2+6)-(4x-8)(x+7)+9(8-4x)
a)\(7x\left(y-4\right)^2-\left(4-y\right)^3=7x\left(4-y\right)^2-\left(4-y\right)^3=\left(4-y\right)^2\left(7x-4+y\right)\)
b)\(\left(4x-8\right)\left(x^2+6\right)-\left(4x-8\right)\left(x+7\right)+9\left(8-4x\right)\)
\(=\left(4x-8\right)\left(x^2+6\right)-\left(4x-8\right)\left(x+7\right)-9\left(4x-8\right)\)
\(=\left(4x-8\right)\left(x^2-x-10\right)=4\left(x-2\right)\left(x^2-x-10\right)\)
a.\(7x.\left(y-4\right)^2-\left(4-y\right)^3\)=\(7x.\left(4-y\right)^2-\left(4-y\right)^3=\left(4-y\right)^2.\left(7x+y-4\right)\)
b.\(\left(4x-8\right).\left(x^2+6\right)-\left(4x-8\right)\left(x+7\right)+9.\left(8-4x\right)\)
=\(\left(4x-8\right)\left(x^2+6-x-7-9\right)=\left(4x-8\right)\left(x^2-x-10\right)\)
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 thành nhân tử:
a)a^4-4b^2
b)9(a+b)^2-4(a-2b)^2
c)4(2a-b)^2-49(a-b)^2
d)4x^4+20x^2+25
e)9x^4+24x^2+16
g)4x^4-16x^2y^3+16y^6
h)9x^6-12x^7+4x^8
i)8x^6-27y^3
k)1/64x^6-125y^3
l)x^6+1
m)x^6-y^6
n)x^9+1
o)x^12-y^4
1.Phân tích đa thức thành nhân tử:
a) a^4-4b^2
b) 9(a+b)^2-4(a-2b)^2
c)4(2a-b)^2-49(a-b)^2
d)4x^4+20x^2+25
e)9x^4+24x^2+16
f)4x^4-16x^2y^3+16y^6
g)9x^6-12x^7+4x^8
h)8x^6-27y^3
k)1/64x^6-125y^3
i)x^6+1
l)x^6-y^6
m)x^9+1
n)x^12-y^4
tĩm biết
a, x^3-0,25x=0
b, x^2-10x=-25
bài này nữa
phân tích thành nhân tử
x^2-9
4X^2-25
X^6-Y^6
9X^2+6XY+Y^2
6X-9-X^2
X^2+4Y^2+4XY
phân tích thành nhân tử:
\(x^2-9=x^2-3^2=\left(x+3\right)\left(x-3\right)\)
\(4x^2-25=\left(2x\right)^2-5^2=\left(2x+5\right)\left(2x-5\right)\)
\(x^6-y^6=\left(x^3\right)^2-\left(y^3\right)^2\)\(=\left(x^3+y^3\right)\left(x^3-y^3\right)\)
\(=\left(x+y\right)\left(x-y\right)\left(x^2+xy+y^2\right)\left(x^2-xy+y^2\right)\)
\(9x^2+6xy+y^2=\left(3x\right)^2+2\cdot3x\cdot1+y^2=\left(3x+y\right)^2\)
\(x^2+4y^2+4xy=x^2+2\cdot x\cdot2y+\left(2y\right)^2=\left(x+2y\right)^2\)
a. \(x^3-0.25x=0\Rightarrow x\left(x^2-\frac{1}{4}\right)=0\)
\(\Rightarrow\orbr{\begin{cases}x=0\\x^2-\frac{1}{4}=0\end{cases}\Rightarrow\orbr{\begin{cases}x=0\\x^2=\frac{1}{4}\end{cases}}}\) \(\Rightarrow\orbr{\begin{cases}x=0\\\orbr{\begin{cases}x=\frac{1}{2}\\x=\frac{-1}{2}\end{cases}}\end{cases}}\)
\(\Rightarrow\orbr{\begin{cases}x=0\\\orbr{\begin{cases}x=\frac{1}{2}\\x=\frac{-1}{2}\end{cases}}\end{cases}}\)=> \(x\in\left\{0;\frac{1}{2};\frac{-1}{2}\right\}\)
b, \(x^2-10x=-25\)\(\Rightarrow x^2-10x+25=0\)
\(\Rightarrow\left(x-5\right)^2=0\Rightarrow x-5=0\Rightarrow x=5\)
a, \(x^2-9=x^2-3x+3x-9\)
\(=x\left(x-3\right)+3\left(x-3\right)=\left(x-3\right)\left(x+3\right)\)
b, \(4x^2-25=\left(2x\right)^2-5^2=\left(2x-5\right)\left(2x+5\right)\)
c, \(x^6-y^6=\left(x^3\right)^2-\left(y^3\right)^2=\left(x^3+y^3\right)\left(x^3-y^3\right)\)
d, \(9x^2+6xy+y^2=\left(3x\right)^2+2\left(3xy\right)+y^2\) \(=\left(3x+y\right)^2\)
e, \(6x-9-x^2=6x-18+9-x^2\) \(=6\left(x-3\right)-\left(x-3\right)\left(x+3\right)\)
\(=\left(x-3\right)\left(6-x-3\right)=\left(x-3\right)\left(3-x\right)\)
f, \(x^2+4y^2+4xy=x^2+2\left(2xy\right)+\left(2y\right)^2\)
\(\left(x+2y\right)^2\)
\(\)
Phân tích đa thức thành nhân tử
a) (4x^2 - 3x - 18)^2 - (4x^2 + 3x)^2
b) 9(x + y - 1)^2 - 4(2x + 3y +1)^2
c) -4x^2 + 12xy - 9y^2 + 25
d) x^2 - 2xy + y^2 - 4m^2 + 4mn - n^2
a) Ta có: \(\left(4x^2-3x-18\right)^2-\left(4x^2+3x\right)^2\)
\(=\left(4x^2-3x-18-4x^2-3x\right)\left(4x^2-3x-18+4x^2+3x\right)\)
\(=\left(-6x-18\right)\left(8x^2-18\right)\)
\(=-6\left(x+3\right)\cdot2\left(4x^2-9\right)\)
\(=-12\left(x+3\right)\left(2x-3\right)\left(2x+3\right)\)
b) Ta có: \(9\left(x+y-1\right)^2-4\left(2x+3y+1\right)^2\)
\(=\left(3x+3y-3\right)^2-\left(4x+6y+2\right)^2\)
\(=\left(3x+3y-3-4x-6y-2\right)\left(3x+3y-3+4x+6y+2\right)\)
\(=-\left(x+3y+5\right)\left(7x+9y-1\right)\)
c) Ta có: \(-4x^2+12xy-9y^2+25\)
\(=-\left(4x^2-12xy+9y^2-25\right)\)
\(=-\left[\left(2x-3y\right)^2-25\right]\)
\(=-\left(2x-3y-5\right)\left(2x-3y+5\right)\)
d) Ta có: \(x^2-2xy+y^2-4m^2+4mn-n^2\)
\(=\left(x^2-2xy+y^2\right)-\left(4m^2-4mn+n^2\right)\)
\(=\left(x-y\right)^2-\left(2m-n\right)^2\)
\(=\left(x-y-2m+n\right)\left(x-y+2m-n\right)\)
a) (4x2-3x-18)2-(4x2+3x)2
=(4x2-3x-18-4x2-3x)(4x2-3x-18+4x2+3x)
=(-6x-18)(8x2-18)
=-48x3+108x-144x2+324