K
Khách

Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.

25 tháng 7 2017

a)\(x^2+4x+4=x^2+2\cdot2\cdot x+2^2=\left(x+2\right)^2\)

b)\(9x^2+42x+49=\left(3x\right)^2+2\cdot3x\cdot7+7^2=\left(3x+7\right)^2\)

c)\(\dfrac{1}{9}-\dfrac{2}{3}y^4+y^8=\left(\dfrac{1}{3}\right)^2-2\cdot\dfrac{1}{3}\cdot y^4+\left(y^4\right)^2=\left(y^4-\dfrac{1}{3}\right)^2\)

25 tháng 7 2017

a) \(x^2+2.2x+2^2\)

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

b)\(\left(3x\right)^2+2.3.7x+7^2\)

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

c) \(\left(\dfrac{1}{3}\right)^2-2.\dfrac{1}{3}.y^4+\left(y^4\right)^2\)

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

21 tháng 8 2023

a) \(x^2+4x+4\)

\(=x^2+2\cdot2\cdot x+2^2\)

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

b) \(4x^2-4x+1\)

\(=\left(2x\right)^2-2\cdot2x\cdot1+1^2\)

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

c) \(x^2-x+\dfrac{1}{4}\)

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

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

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

\(=\left[2\left(x+y\right)\right]^2-2\cdot2\left(x+y\right)\cdot1+1^2\)

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

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

20 tháng 8 2016

a. Đề đúng phải là \(\frac{1}{4}a^2+2ab^2+4b^4\)hoặc \(\frac{1}{4}a^2+2ab+4b^2\)

Ở đây mình giải trường hợp 2, bạn dựa theo để giải trường hợp 1 nhé :))

\(\frac{1}{4}a^2+2ab+4b^2\)

\(=\left(\frac{1}{2}a\right)^2+2ab+\left(2b\right)^2\)

\(=\left(\frac{1}{2}a\right)^2+2.\frac{1}{2}a.2b+\left(2b\right)^2\)

\(=\left(\frac{1}{2}a+2b\right)^2\)

b. \(25+10x+x^2\)

\(=x^2+2.x.5+5^2\)

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

c. \(\frac{1}{9}-\frac{2}{3}y^4+y^8\)

\(=\left(y^4\right)^2-2.y^4.\frac{1}{3}+\left(\frac{1}{3}\right)^2\)

\(=\left(y^4-\frac{1}{3}\right)^2\)

a: \(\left(3x-1\right)\left(9x^2+3x+1\right)=27x^3-1\)

b: \(\left(1-\dfrac{x}{5}\right)\left(\dfrac{x^2}{25}+\dfrac{x}{5}+1\right)=1-\dfrac{x^3}{125}\)

c: \(\left(x+3y\right)\left(x^2-3xy+9y^2\right)=x^3+27y^3\)

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

22 tháng 2 2019

a) ( 2 x   +   1 ) 2 .                     b) ( 3 x   –   2 ) 2 .

c) 1 2 ab 2 + 1 2 .                  d) ( 4 uv 2   –   1 ) 2 .

a)x2-6x+9

=x2-2.x.3+32

=(x-3)2

b)4x2+4x+1

=(2x)2+2.2x.1+12

=(2x+1)2

c)4x2+12xy+9y2

=(2x)2+2.2x.3y+(3y)2

=(2x+3y)2

d)4x4-4x2+4

=(2x2)2-2.2x2.2+22

=(2x2-2)2

30 tháng 9 2021

a)
=(x-2)3
b)\(\left(2-x\right)^3\)
c)\(\left(x+\dfrac{1}{3}\right)^3\)
d)\(\left(\dfrac{x}{2}+y\right)^3\)
e)
\(=\left(x-1\right)^2\left(x-1-15\right)+25\left[3\left(x-1\right)-5\right]\)
\(=\left(x-1\right)^2\left(x-16\right)+25\left(3x-3-5\right)\)
\(=\left(x-1\right)^2\left(x-16\right)+25\left(3x-8\right)\)
 

29 tháng 6 2023

1, \(x^2+2xy+y^2=\left(x+y\right)^2\)

2, \(4x^2+12x+9=\left(2x\right)^2+2\cdot3\cdot2x+3^2=\left(2x+3\right)^2\)

3, \(x^2+5x+\dfrac{25}{4}=x^2+2\cdot\dfrac{5}{2}\cdot x+\left(\dfrac{5}{2}\right)^2=\left(x+\dfrac{5}{2}\right)^2\)

4, \(16x^2-8x+1=\left(4x\right)^2-2\cdot4x\cdot1+1^2=\left(4x-1\right)^2\)

5, \(x^2+x+\dfrac{1}{4}=x^2+2\cdot\dfrac{1}{2}\cdot x+\left(\dfrac{1}{2}\right)^2=\left(x+\dfrac{1}{2}\right)^2\)

1: =(x+y)^2

2: =(2x+3)^2

3: =(x+5/2)^2

4: =(4x-1)^2

5: =(x+1/2)^2

6: =(x-3/2)^2

7: =(x+1)^3

8: =(1/2x+1)^2

9: =(3y-1/3)^3

10: =(2x+y)^3

a:Sửa đề: \(\dfrac{1}{4}a^2+2ab+4b^2\)

\(=\left(\dfrac{1}{2}a\right)^2+2\cdot\dfrac{1}{2}a\cdot2b+\left(2b\right)^2\)

\(=\left(\dfrac{1}{2}a+2b\right)^2\)

b: Sửa đề:\(y^4-\dfrac{1}{3}y^4+\dfrac{1}{36}\)

\(=y^8-2\cdot y^4\cdot\dfrac{1}{6}+\dfrac{1}{36}\)

\(=\left(y^4-\dfrac{1}{6}\right)^2\)

27 tháng 10 2023

a. $x^2+4x+4$

$=x^2+2\cdot x\cdot2+2^2$

$=(x+2)^2$

b. $x^2-6xy+9y^2$

$=x^2-2\cdot x\cdot3y+(3y)^2$

$=(x-3y)^2$

c. $4x^2+12x+9$

$=(2x)^2+2\cdot2x\cdot3+3^2$

$=(2x+3)^2$

d. $x^2-x+\dfrac14$

$=x^2-2\cdot x\cdot \dfrac12+\Bigg(\dfrac12\Bigg)^2$

$=\Bigg(x-\dfrac12\Bigg)^2$

27 tháng 10 2023

`x^2 +4x+4`

`=x^2+2*x*2+2^2`

`=(x+2)^2`

__

`x^2-6xy+9y^2`

`=x^2 - 2*x*3y+(3y)^2`

`=(x-3y)^2`

__

`4x^2 +12x+9`

`=(2x)^2 +2*2x*3+3^2`

`=(2x+3)^2`

__

`x^2-x+1/4`

`=x^2 - 2*x*1/2 +(1/2)^2`

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