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16 tháng 7 2018

a) \(x^2-x+\frac{1}{4}=\left(x-\frac{1}{2}\right)^2\)

b) \(49x^2+28x+4=\left(7x+2\right)^2\)

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

d) \(x^3-8x^2y+27xy^2-27y^3=\left(x-3y\right)^3\)

e) \(8+125x^3=\left(2+5x\right)\left(4-10x+25x^2\right)\)

f) \(27x^3-64=\left(3x-4\right)\left(9x^2+12x+16\right)\)

16 tháng 7 2018

a/ \(x^2-x+\frac{1}{4}\) \(=x^2-2.\frac{1}{2}x+\left(\frac{1}{2}\right)^2\) \(=\left(x-\frac{1}{2}\right)^2\)

b/ \(49x^2+28x+4\) \(=\) \(\left(7x\right)^2+2.7x.2+2^2\) \(=\left(7x+2\right)^2\)

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

d/\(x^3-9x^2y+27xy^2-27y^3\) \(=x^3-3.x^2.3y+3.x.9y^2-\left(3y\right)^3\) \(=\left(x-3y\right)^3\)

e/ \(8+125x^3\)\(=\left(2+5x\right)\left(4-10x+25x\right)\) 

d/ \(27x^3-64=\left(3x-4\right)\left(9x^2+12x+16\right)\)

22 tháng 8 2023

a) \(x^4-y^4\)

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

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

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

b) \(x^2-3y^2\)

\(=x^2-\left(y\sqrt{3}\right)^2\)

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

c) \(\left(3x-2y\right)^2-\left(2x-3y\right)^2\)

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

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

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

d) \(9\left(x-y\right)^2-4\left(x+y\right)^2\)

\(=\left[3\left(x-y\right)+2\left(x+y\right)\right]\left[3\left(x-y\right)-2\left(x+y\right)\right]\)

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

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

e) \(\left(4x^2-4x+1\right)-\left(x+1\right)^2\)

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

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

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

f) \(x^3+27\)

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

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

g) \(27x^3-0,001\)

\(=\left(3x\right)^3-\left(0,1\right)^3\)

\(=\left(3x-0,1\right)\left(9x^2+0,3x+0,01\right)\)

h) \(125x^3-1\)

\(=\left(5x\right)^3-1^3\)

\(=\left(5x-1\right)\left(25x^2+5x+1\right)\)

28 tháng 9 2021

\(a,=\left(x^2-y^2\right)\left(x^2+y^2\right)=\left(x-y\right)\left(x+y\right)\left(x^2+y^2\right)\\ b,=\left(x-\sqrt{3}y\right)\left(x+\sqrt{3}y\right)\\ c,=\left[3x-2y-2\left(x+y\right)\right]\left[3x-2y+2\left(x+y\right)\right]\\ =5x\left(x-4y\right)\\ d,=\left[3\left(x-y\right)-2\left(x+y\right)\right]\left[3\left(x-y\right)+2\left(x+y\right)\right]\\ =\left(3x-3y-2x-2y\right)\left(3x-3y+2x+2y\right)\\ =\left(x-5y\right)\left(5x-y\right)\\ f,=\left(x+3\right)\left(x^2-3x+9\right)\\ g,=\left(3x-0,1\right)\left(9x^2+0,3x+0,01\right)\\ h,=\left(5x-1\right)\left(25x^2+5x+1\right)\)

28 tháng 9 2021

\(a)x^4-y^4=(x^2-y^2)(x^2+y^2)=(x-y)(x+y)(x^2+y^2)\\ b)x^2-3y^2=\\ c)(3x-2y)^2-4(x+y)^2=(3x-2y)^2-[2(x+y)]^2\\=(3x-2y+2x+2y)(3x-2y-2x-2y)=5x(x-4y)\\ d)9(x-y)^2-4(x+y)^2=[3(x-y)]^2-[2(x+y)]^2=(3x-3y+2x+2y)(3x-3y-2x-2y)\\=(5x-y)(x-5y)\\ f)x^3+27=(x+3)(x^2-3x+9)\\ g)27x^3-0,001=(3x-0,1)(9x+0,3x+0,01)\\ h)125x^3-1=(5x-1)(25x^2+5x+1)\)

4 tháng 10 2021

1) \(\dfrac{1}{27}+a^3=\left(\dfrac{1}{3}+a\right)\left(\dfrac{1}{9}-\dfrac{a}{3}+a^2\right)\)

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

3) \(=\left(\dfrac{1}{2}x+2y\right)\left(\dfrac{1}{4}x-xy+4y^2\right)\)

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

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

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

7) \(=\left(x-5\right)\left(x^2+5x+25\right)\)

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

9) \(=\left(\dfrac{1}{4}x^2-5y\right)\left(\dfrac{1}{16}x^4+\dfrac{5}{4}x^2y+25y^2\right)\)

10) \(=\left(\dfrac{1}{2}x-2\right)\left(\dfrac{1}{4}x^2+x+4\right)\)

11) \(=\left(x+2\right)^3\)

12) \(=\left(x+3\right)^3\)

 

4 tháng 10 2021

cảm ơn bạn ;-;

 

14 tháng 10 2019

b) \(-4x^2-4x-1\)

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

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

c) \(\frac{4}{9}x^2-25y^2\)

\(=\left(\frac{2}{3}x+5y\right)\left(\frac{2}{3}x-5y\right)\)

d) \(\frac{1}{27}x^3-8\)

\(=\left(\frac{1}{3}x-2\right)\left(\frac{1}{9}x+\frac{2}{3}x+4\right)\)

22 tháng 7 2018

a) \(^{x^4-y^4}\)

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

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

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

c) \(\left(3x-2y\right)^2-\left(2x-3y\right)^2\)

\(=\left[\left(3x-2y\right)+\left(2x-3y\right)\right].\left[\left(3x-2y\right)-\left(2x-3y\right)\right]\)

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

b) \(x^2-3y^2\)

\(=\left(x-3y\right)\left(x+3y\right)\)

d) \(9\left(x-y\right)^2-4\left(x+y\right)^2\)

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

\(=\left(x-y\right).\left(9+4\right)\)

\(=\left(x-y\right).13\)

\(=13\left(x-y\right)\)

f) \(x^3+27\)

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

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

h) \(125x^3-1\)

\(=\left(5x\right)^3-1^3\)

\(=\left(5x-1\right)\left(5x^2+5x.1+1^2\right)\)

\(=\left(5x-1\right)\left(5x^2+5x+1\right)\)

22 tháng 7 2018

\(a,x^4-y^4=\left(x^2+y^2\right)\left(x^2-y^2\right)=\left(x^2+y^2\right)\left(x+y\right)\left(x-y\right)\)

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

cn lại tg tự nha bn

20 tháng 12 2016

n *o biets

18 tháng 6 2016

a) = (x + 3)2 - y2 = (x + 3 - y)(x + 3 + y)

b) = x2(x - 3) -4(x - 3) = (x - 3)(x2 - 4) = (x - 3)(x - 2)(x + 2)

c) = 3x(x - y) - 5(x - y) = (x - y)(3x - y)

d) Nhầm đề. tui sửa lại x3 + y3 + 2x2 - 2xy + 2y2

= x3 + y3 + 2(x2 - xy + y2) = (x + y)(x2 - xy + y2) + 2(x2 - xy + y2) = (x2 - xy + y2)(x + y + 2)

e) = x4 - x3 - x3 + x2 - x2 + x + x - 1 = x3(x - 1) - x2(x - 1) - x(x - 1) + x - 1 = (x - 1)(x3 - x2 - x + 1) = (x - 1)(x - 1)(x2 - 1) = (x - 1)3(x + 1)

f) = x3 - 3x2 - x2 + 3x + 9x - 27 = x2(x - 3) - x(x - 3) + 9(x - 3) = (x-3)(x2 - x + 9)

g) chắc là 3xyz 

= x2y + xy2 + y2z + yz2 + x2z + xz2 + 3xyz = x2y + xy2 + xyz + y2z + yz2 + xyz + x2z + xz2 + xyz = (x + y + z)(xy + yz + xz)

h) = 23 -(3x)3 = (2 - 3x)(4 + 6x + 9x2)

i) = (x + y - x + y)(x + y + x - y) = 2y*2x = 4xy

k) = (x3 - y3)(x3 + y3) = (x - y)(x2 + xy +y2)(x + y)(x2 - xy +y2).

a: \(=\left(x+1+5\right)\left(x+1-5\right)=\left(x+6\right)\left(x-4\right)\)

b: =(1-2x)(1+2x)

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

d: =(x+3)^3

e: \(=\left(2x-y\right)^3\)

f: =(x+2y)(x^2-2xy+4y^2)

30 tháng 6 2018

a)  \(49x^2-56x+16\) 

\(=\left(7x-4\right)^2\)

\(=\left(7.2-4\right)^2=100\)

b) mk chỉnh lại đề

  \(27x^3+54x^2+36x+8\)  

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

\(=\left[3.\left(-2\right)+2\right]^3=-64\)

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

\(=6x^2+7x+5\)

\(=6.\left(-\frac{2}{5}\right)^2+7.\left(-\frac{2}{5}\right)+5\)

\(=\frac{79}{25}\)

30 tháng 6 2018

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