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5 tháng 8 2018

a) 27x^3 –27x^2 +18x –4

= 27x^3 –9x^2–18x^2+6x + 12x –4

= 9x^2 (3x–1) – 6x (3x–1) +4(3x–1)

= (3x-1) (9x^2–6x+4)

b)2x^3–2x^2+5x+3

= 2x^3+x^2–2x^2–x+6+3

= x^2(2x+1)-x^2(2x+1)+3(2x+1)

= (2x+1) 3

c) 2x^4 + 5x^3+13x^2+25x+15 
=2x^3(x+1)+3x^2(x+1)+10x(x+1)+15(x+1) 
=(x+1)(x^2(2x+3)+5(2x+3)) 
=(x+1)(2x+3)(x^2+5)

a: x^3-7x-6

=x^3-x-6x-6

=x(x-1)(x+1)-6(x+1)

=(x+1)(x^2-x-6)

=(x-3)(x+2)(x+1)

b: =2x^3+x^2-2x^2-x+6x+3

=x^2(2x+1)-x(2x+1)+3(2x+1)

=(2x+1)(x^2-x+3)

c: =2x^3-3x^2-2x^2+3x+2x-3

=x^2(2x-3)-x(2x-3)+(2x-3)

=(2x-3)(x^2-x+1)

d: =2x^3+x^2+2x^2+x+2x+1

=(2x+1)(x^2+x+1)

e: =3x^3+x^2-3x^2-x+6x+2

=(3x+1)(x^2-x+2)

f: =27x^3-9x^2-18x^2+6x+12x-4

=(3x-1)(9x^2-6x+4)

29 tháng 8 2023

a) \(x^3-7x-6\)

\(=x^3-x-6x-6\)

\(=\left(x^3-x\right)-\left(6x+6\right)\)

\(=x\left(x^2-1\right)-6\left(x+1\right)\)

\(=x\left(x+1\right)\left(x-1\right)-6\left(x+1\right)\)

\(=\left(x+1\right)\left(x^2-x-6\right)\)

b) \(2x^3-x^2+5x+3\)

\(=2x^3+x^2-2x^2-x+6x+3\)

\(=\left(2x^3+x^2\right)-\left(2x^2+x\right)+\left(6x+3\right)\)

\(=x^2\left(2x+1\right)-x\left(2x+1\right)+3\left(2x+1\right)\)

\(=\left(x^2-x+3\right)\left(2x+1\right)\)

c) \(2x^3-5x^2+5x+1\)

\(=2x^3-3x^2-2x^2+3x+2x-3\)

\(=\left(2x^3-3x^2\right)-\left(2x^2-3x\right)+\left(2x-3\right)\)

\(=x^2\left(2x-3\right)-x\left(2x-3\right)+\left(2x-3\right)\)

\(=\left(x^2-x+1\right)\left(2x-3\right)\)

d) \(2x^3+3x^2+3x+1\)

\(=2x^3+x^2+2x^2+x+2x+1\)

\(=\left(2x^3+x^2\right)+\left(2x^2+x\right)+\left(2x+1\right)\)

\(=x^2\left(2x+1\right)+x\left(2x+1\right)+\left(2x+1\right)\)

\(=\left(2x+1\right)\left(x^2+x+1\right)\)

e) \(3x^3-2x^2+5x+2\)

\(=3x^3+x^2-3x^2-x+6x+2\)

\(=\left(3x^3+x^2\right)-\left(3x^2+x\right)+\left(6x+2\right)\)

\(=x^2\left(3x+1\right)-x\left(3x+1\right)+2\left(3x+1\right)\)

\(=\left(3x-1\right)\left(x^2-x+2\right)\)

f) \(27x^3-27x^2+18x-4\)

\(=27x^3-9x^2-18x^2+6x+12x-4\)

\(=\left(27x^3-9x^2\right)-\left(18x^2-6x\right)+\left(12x-4\right)\)

\(=9x^2\left(3x-1\right)-6x\left(3x-1\right)+4\left(3x-1\right)\)

\(=\left(3x-1\right)\left(9x^2-6x+4\right)\)

13 tháng 1 2020

con dồ ngu si

13 tháng 1 2020

a) \(2x^3-x^2+5x+3\)

\(=2x^3-2x^2+x^2+6x-x+3\)

\(=\left(2x^3-2x^2+6x\right)+\left(x^2-x+3\right)\)

\(=2x\left(x^2-x+3\right)+\left(x^2-x+3\right)\)

\(=\left(2x+1\right)\left(x^2-x+3\right)\)

b)  \(27x^3-27x^2+18x-4\)

\(=27x^3-18x^2-9x^2+12x+6x-4\)

\(=\left(27x^3-18x^2+12x\right)-\left(9x^2-6x+4\right)\)

\(=3x\left(9x^2-6x+4\right)-\left(9x^2-6x+4\right)\)

\(=\left(3x-1\right)\left(9x^2-6x+4\right)\)

8 tháng 10 2016

b) 3x4-3x3+9x3-9x2-24x2+24x-48x+48

=3x3(x-1)+9x2(x-1)-24x(x-1)-48(x-1)

=(x-1)(3x3+9x2-24x-48)

=3(x-1)(x3+3x2-8x-16)

11 tháng 9 2020

a) 27x3 - 27x2 + 18x - 4 ( sửa thành +18x nhé , chứ để như kia khó phân tích lắm :< )

= 27x3 - 18x2 - 9x2 + 12x + 6x - 4

= ( 27x3 - 18x2 + 12x ) - ( 9x2 - 6x + 4 )

= 3x( 9x2 - 6x + 4 ) - ( 9x2 - 6x + 4 )

= ( 9x2 - 6x + 4 )( 3x - 1 )

b) 2x3 - x2 + 5x + 3 

= 2x3 - 2x2 + x2 + 6x - x + 3

= ( 2x3 - 2x2 + 6x ) + ( x2 -x + 3 )

= 2x( x2 - x + 3 ) + ( x2 - x + 3 )

= ( x2 - x + 3 )( 2x + 1 )

c) ( x2 - 3 )2 + 16 

= x4 - 6x2 + 9 + 16

= x4 - 6x2 + 25 

= x4 + 10x2 + 25 - 16x2

= ( x4 + 10x2 + 25 ) - 16x2

= ( x2 + 5 )2 - ( 4x )2

= ( x2 - 4x + 5 )( x2 + 4x + 5 )

16 tháng 10 2016

\(2x^2+3x-27=2x^2-6x+9x-27=2x\left(x-3\right)+9\left(x-3\right)=\left(2x+9\right)\left(x-3\right)\)

\(x^3-7x+6=x^3-x-6x+6=x\left(x^2-1\right)-6\left(x-1\right)=x\left(x-1\right)\left(x+1\right)-6\left(x-1\right)=\left(x-1\right)\left(x^2+x-6\right)\)

\(x^3+5x^2+8x+4=x^3+x^2+4x^2+8x+4=x^2\left(x+1\right)+4\left(x^2+2x+1\right)=x^2\left(x+1\right)+4\left(x+1\right)^2\)

\(=\left(x+1\right)\left(x^2+4x+4\right)=\left(x+1\right)\left(x+2\right)^2\)

\(27x^3-27x^2+18x-4=27x^3-9x^2-18x^2+6x+12x-4\)

\(=9x^2\left(3x-1\right)-6x\left(3x-1\right)+4\left(3x-1\right)=\left(3x-1\right)\left(9x^2-6x+4\right)\)

\(x^2+4x+3\)

\(=\left(x+1\right)\left(x+3\right)\)

\(2x^2+3x-5\)

\(\left(x-1\right)\left(x+\frac{5}{2}\right)\)

9 tháng 8 2016

a)=-4x2+8x-4

=-[(2x)2-8x+4]

=-(2x-2)2

9 tháng 8 2016

b)=x3-3x2+3x2-9x+2x-6

=x2(x-3)+3x(x-3)+2(x-3)

=(x-3)(x2+3x+2)

=(x-3)(x2+x+2x+2)

=(x-3)[x(x+1)+2(x+1)]

=(x-3)(x+1)(x+2)

16 tháng 9 2017

Là hằng đẳng thức số 5 ý

16 tháng 9 2017

= (3x-1)3

a: \(x^3-9x^2+6x+16\)

\(=x^3-8x^2-x^2+8x-2x+16\)

\(=x^2\left(x-8\right)-x\left(x-8\right)-2\left(x-8\right)\)

\(=\left(x-8\right)\left(x^2-x-2\right)\)

\(=\left(x-8\right)\left(x-2\right)\left(x+1\right)\)

b: \(x^3-x^2-x-2\)

\(=x^3-2x^2+x^2-2x+x-2\)

\(=x^2\left(x-2\right)+x\left(x-2\right)+\left(x-2\right)\)

\(=\left(x-2\right)\cdot\left(x^2+x+1\right)\)

c: \(x^3+x^2-x+2\)

\(=x^3+2x^2-x^2-2x+x+2\)

\(=x^2\left(x+2\right)-x\left(x+2\right)+\left(x+2\right)\)

\(=\left(x+2\right)\left(x^2-x+1\right)\)

d: \(x^3-6x^2-x+30\)

\(=x^3+2x^2-8x^2-16x+15x+30\)

\(=x^2\left(x+2\right)-8x\left(x+2\right)+15\left(x+2\right)\)

\(=\left(x+2\right)\left(x^2-8x+15\right)\)

\(=\left(x+2\right)\left(x-3\right)\left(x-5\right)\)

e: Sửa đề: \(x^3-7x-6\)

\(=x^3-x-6x-6\)

\(=x\left(x^2-1\right)-6\left(x+1\right)\)

\(=x\left(x-1\right)\left(x+1\right)-6\left(x+1\right)\)

\(=\left(x+1\right)\left(x^2-x-6\right)\)

\(=\left(x+1\right)\left(x-3\right)\left(x+2\right)\)

f: \(27x^3-27x^2+18x-4\)

\(=27x^3-9x^2-18x^2+6x+12x-4\)

\(=9x^2\left(3x-1\right)-6x\left(3x-1\right)+4\left(3x-1\right)\)

\(=\left(3x-1\right)\left(9x^2-6x+4\right)\)

g: \(2x^3-x^2+5x+3\)

\(=2x^3+x^2-2x^2-x+6x+3\)

\(=x^2\left(2x+1\right)-x\left(2x+1\right)+3\left(2x+1\right)\)

\(=\left(2x+1\right)\left(x^2-x+3\right)\)

h: \(\left(x^2-3\right)^2+16\)

\(=x^4-6x^2+9+16\)

\(=x^4-6x^2+25\)

\(=x^4+10x^2+25-16x^2\)

\(=\left(x^2+5\right)^2-\left(4x\right)^2\)

\(=\left(x^2+5+4x\right)\left(x^2+5-4x\right)\)