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27 tháng 12 2017

\(x^4-16=\left(x^2\right)^2-4^2=\left(x^2-4\right)\left(x^2+4\right)=\left(x-2\right)\left(x+2\right)\left(x^2+4\right)\)

\(x^2-64=x^2-8^2=\left(x-8\right)\left(x+8\right)\)

27 tháng 12 2017

\(x^4-16=\left(x^2\right)^2-4^2=\left(x^2-4\right)\left(x^2+4\right)=\left(x-2\right)\left(x+2\right)\left(x^2+4\right)\\ x^2-64=x^2-8^2=\left(x-8\right)\left(x+8\right)\)

8 tháng 7 2019

3. ( 22 + 1 ).( 24 + 1 ).( 28 + 1 )......( 264 + 1 ) + 1

= ( 22 - 1 ).( 22 + 1 ).( 24 + 1 ).( 28 + 1 )....( 264 + 1 ) + 1

= ( 24 - 1 ).( 24 + 1 ).( 28 + 1 )......( 264 + 1 ) + 1

= ( 28 + 1 ).....( 264 + 1 )  + 1

= ( 264 - 1 ).( 264 + 1 ) + 1

=  2128 - 1 + 1

= 2128

8 tháng 7 2019

8.( 32 + 1 ).( 34 + 1 ).( 38 + 1 )....( 3128 + 1 ) + 1

= ( 32 - 1 ).( 32 + 1 ).( 34 + 1 ).( 38 + 1 )....( 3128 + 1 ) + 1

= ( 34 - 1 ).( 34 + 1 ).( 38 + 1 )....( 3128 + 1 ) + 1

= ( 38 - 1 ).( 38 + 1 )....( 3128 + 1 ) + 1

= ( 316 - 1 )......( 3128 + 1 ) + 1

= ( 3128 - 1 ).( 3128 + 1 ) + 1

=  3256 - 1 + 1

= 3256

3 tháng 8 2018

b, \(x^2-6x-2=x^2-6x+9-11=\left(x-3\right)^2-\sqrt{11}^2\)

\(=\left(x-3-\sqrt{11}\right)\left(x-3+\sqrt{11}\right)\)

c,\(9x^2+6x-1=\left(3x\right)^2+2.3x+1-2=\left(3x+1\right)^2-\sqrt{2}^2\)

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

d,\(x^8+64=\left(x^4\right)^2+8^2+16x^4-16x^4\)

\(=\left(x^4+8\right)^2-\left(4x^2\right)^2=\left(x^4+4x^2+8\right)\left(x^4-4x^2+8\right)\)

e,\(81x^4+4=\left(9x^2\right)^2+2^2+36x^2-36x^2=\left(9x^2+2\right)^2-\left(6x\right)^2\)

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

g,\(x^8+x^7+1\)

\(=\left(x^8+x^7+x^6\right)+\left(x^5+x^4+x^3\right)+\left(x^2+x+1\right)-\left(x^6+x^5+x^4\right)-\left(x^3+x^2+x\right)\)

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

17 tháng 8 2016

1)x2-8x-9

= x^2 - 9x +x -9

= x(x+1) - 9 (x+1)

= (x-9) (x+1)

2)x2+3x-18

3)x3-5x2+4x

=x^3 - 4x^2 - x^2 + 4x 

= x^2 (x-1) - 4x(x-1)

= (x^2 - 4x) (x-1)

= x(x-4)(x-1)

4)x3-11x2+30x

5)x3-7x-6

6)x16-64

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

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

7)x3-5x2+8x-4

8)x2-3x+2

= x^2 - 2x - x +2

= x(x-1) -2(x-1)

= (x-2)(x-1)

17 tháng 8 2016

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

4)    \(x\left(x-6\right)\left(x-5\right)\)         5)\(\left(x-3\right)\left(x+1\right)\left(x+2\right)\)                               6)   ........

7)  \(\left(x-1\right)\left(x-2\right)\left(x-2\right)\)          8)   \(\left(x-2\right)\left(x-1\right)\)

15 tháng 9 2018

\(\left(x-2\right)\left(x+2\right)\left(x^2+2^2\right)\left(x^4+2^4\right)\left(x^8+2^8\right)-x^{16}\)

\(=\left(x^2-2^2\right)\left(x^2+2^2\right)\left(x^4+2^4\right)\left(x^8+2^8\right)-x^{16}\)

\(=\left(x^4-2^4\right)\left(x^4+2^4\right)\left(x^8+2^8\right)-x^{16}\)

\(=\left(x^8-2^8\right)\left(x^8+2^8\right)-x^{16}\)

\(=\left(x^{16}-2^{16}\right)-x^{16}\)

\(=x^{16}-2^{16}-x^{16}\)

\(\left(-2\right)^{16}=65536\)

22 tháng 7 2017

1. \(125x^3+y^6=\left(5x\right)^3+\left(y^2\right)^3\)

\(=\left(5x+y^2\right)\left[\left(5x\right)^2-5x.y^2+\left(y^2\right)^2\right]\)

\(=\left(5x+y^2\right)\left(25x^2-5xy^2+y^4\right)\)

2. \(4x\left(x-2y\right)+8y\left(2y-x\right)\)

\(=4x\left(x-2y\right)-8y\left(x-2y\right)\)

\(=\left(x-2y\right)\left(4x-8y\right)\)

3. \(25\left(x-y\right)^2-16\left(x+y\right)^2\)

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

\(=\left[5\left(x-y\right)-4\left(x+y\right)\right]\left[5\left(x-y\right)+4\left(x+y\right)\right]\)

\(=\left(5x-5y-4x-4y\right)\left(5x-5y+4x+4y\right)\)

\(=\left(x-9y\right)\left(9x-y\right)\)

4. \(x^4-x^3-x^2+1\)

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

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

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

5. \(a^3x-ab+b-x\)

\(=a^3x-x-ab+b\)

\(=x\left(a^3-1\right)-b\left(a-1\right)\)

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

\(=\left(a-1\right)\left[x\left(a^2+a+1\right)-b\right]\)

6. \(x^3-64=x^3-4^3\)

\(=\left(x-4\right)\left(x^2+4x+16\right)\)

7. \(0,125\left(a+1\right)^3-1\)

\(=\left[0,5\left(a+1\right)\right]^3-1^3\)

\(=\left[0,5\left(a+1\right)-1\right]\left\{\left[0,5\left(a+1\right)\right]^2+\left[0,5\left(a+1\right).1\right]+1^2\right\}\)

\(=\left[0,5\left(a+1-2\right)\right]\left[0,25a^2+0,5a+0,25+0,5a+0,5+1\right]\)

\(=\left[0,5\left(a-1\right)\right]\left(0,25a^2+a+1,75\right)\)

8. \(9\left(x+5\right)^2-\left(x-7\right)^2\)

\(=\left[3\left(x+5\right)\right]^2-\left(x-7\right)^2\)

\(=\left(3x+15-x+7\right)\left(3x+15+x-7\right)\)

\(=\left(2x+22\right)\left(4x+8\right)\)

9. \(49\left(y-4\right)^2-9\left(y+2\right)^2\)

\(=\left[7\left(y-4\right)\right]^2-\left[3\left(y+2\right)\right]^2\)

\(=\left(7y-28-3y-6\right)\left(7y-28+3y+6\right)\)

\(=\left(4y-34\right)\left(10y-22\right)\)

10. \(x^2y+xy^2-x-y=xy\left(x+y\right)-\left(x+y\right)\)

\(=\left(x+y\right)\left(xy-1\right)\)

11. \(x^3+3x^2+3x+1-27z^3\)

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

\(=\left(x+1-3z\right)\left(x^2+2x+1+3xz+3z+9z^2\right)\)

12. \(x^2-y^2-x+y=\left(x-y\right)\left(x+y\right)-\left(x-y\right)\)

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

20 tháng 8 2021

eddddddd

17 tháng 8 2015

a) x^4 - 2x^2 + 1 = 0 

=> ( x^2 - 1 )^2 = 0 

=> x^2 - 1 = 0 

=> x^2 = 1 

=> x = 1 hoặc x = -1 

4 tháng 12 2016

a) x4-2x2+1=0

(thang Tran giải rồi nhé)

b) x4-2x2-8=0

<=> x^4 - 2x^2 +1 -9 =0 

<=>  (x^2 -1)^2 -9 =0

\(\Leftrightarrow\orbr{\begin{cases}x^2-1=-3\\x^2-1=3\end{cases}\Leftrightarrow\orbr{\begin{cases}x^2=-2\left(VN\right)\\x=+_-\sqrt{2}\end{cases}}}\)

Vậy x=+- căn 2

c) x4-4x2-60=0

\(\Leftrightarrow x^4-4x^2+4-64=0\)

\(\Leftrightarrow\left(x^2-2\right)-64=0\)

\(\Leftrightarrow\left(x^2+62\right)\left(x^2-66\right)=0\)

\(\Leftrightarrow\orbr{\begin{cases}x^2+62=0\\x^2-66=0\end{cases}\Leftrightarrow\orbr{\begin{cases}x^2=-62\left(VN\right)\\x^2=+_-\sqrt{66}\end{cases}}}\)

Vậy x=+- căn 66

d) x6-16x2+64=0