K
Khách

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

7 tháng 8 2018

\(9x^2+24xy+16y^2\)

\(=\left(3x\right)^2+2\cdot3x\cdot4y+\left(4y\right)^2\)

\(=\left(3x+4y\right)^2\)

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

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

\(a^4-b^4=\left(a^2-b^2\right)\left(a^2+b^2\right)=\left(a-b\right)\left(a+b\right)\left(a^2+b^2\right)\)

\(\left(a^2+9\right)^2-36a^2\)

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

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

7 tháng 8 2018

a/ \(9x^2+24xy+16y^2=\left(3x\right)^2+2\cdot3x\cdot4y+\left(4y\right)^2=\left(3x+4y\right)^2\)

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

c/ \(a^4-b^4=\left(a^2-b^2\right)\left(a^2+b^2\right)=\left(a-b\right)\left(a+b\right)\left(a^2+b^2\right)\)

d/ \(\left(a^2+9\right)^2-36a^2=\left(a^2+9-6a\right)\left(a^2+9+6a\right)=\left(a-3\right)^2\cdot\left(a+3\right)^2=\left[\left(a-3\right)\left(a+3\right)\right]^2=\left(a^2-9\right)^2\)

9 tháng 10 2018

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

b) \(4x^2+4x+1=\left(2x\right)^2+2\cdot2x\cdot1+1^2=\left(2x+1\right)^2\)

c) \(1+12x+36x^2=1^2+2\cdot1\cdot6x+\left(6x\right)^2=\left(1+6x\right)^2\)

d) \(9x^2-24xy+16y^2=\left(3x\right)^2-2\cdot3x\cdot4y+\left(4y\right)^2=\left(3x-4y\right)^2\)

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

f) \(-8x^3+27=3^3-\left(2x\right)^3=\left(3-2x\right)\left(9+6x+4x^2\right)\)

19 tháng 9 2016

a)27x2.(y-1)9x3.(1-y)

=27x2.(y-1)+9x3.(y-1)

=9x2(y-1)[3+x]

b)8x3 + 1/27

=(2x)3 + (\(\frac{1}{3}\))3

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

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

c)49.(y-4)2-9.(y+2)2
=[7(y-4)]2-[3(y+2)]2
=[7(y-4)+3(y+2)][7(y-4)-3(y+2)]
=(7y-28+3y+6)(7y-28-3y-6)
=(10y-22)(4y-34)

 

19 tháng 9 2016

a) 27x( y - 1) - 9x( 1 - y)

=27x2 (y-1) + 9x3 ( y - 1 )

= (27x2 + 9x3) ( y -1 )

=9x2 ( x + 3) ( y - 1)

b)8x3+1/27

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

\(=\left(\frac{2x}{9}+\frac{1}{27}\right)\left(36x^2-6x+1\right)\)

c)49 ( y - 4 )2 - 9 ( y + 2)2 

= [7(y - 4)]2 - [3(y + 2)]2

= (7y - 28 + 3y + 6)(7y - 28 - 3y - 6)

= (10y - 22)(4y - 34)

4(5y - 11)(2y - 34)

 

 

 

 

 

16 tháng 8 2018

a) \(4x^2-12x+9=\left(2x\right)^2-2.2x.3+3^2=\left(2x-3\right)^2\)

b) \(4x^2+4x+1=\left(2x\right)^2+2.2x.1+1^2=\left(2x+1\right)^2\)

c) \(1+12x+36x^2=1^2+2.6x.1+\left(6x\right)^2=\left(1+6x\right)^2\)

d) \(9x^2-24xy+16y^2=\left(3x\right)^2-2.3x.4y+\left(4y\right)^2=\left(3x-4y\right)^2\)

f) \(-x^2+10x-25=-\left(x^2-10x+25\right)=-\left(x-5\right)^2\)

g) \(-16a^4b^6-24a^5b^5-9a^6b^4=-\left(16a^4b^6+24a^5b^5+9a^6b^4\right)\)

                             \(=-\left[\left(4a^2b^3\right)^2+2.4a^2b^3.3a^3b^2+\left(3a^3b^2\right)^2\right]\)

                              \(=-\left(4a^2b^3+3a^3b^2\right)^2\)

h) \(25x^2-20xy+4y^2=\left(5x\right)^2-2.5x.2y+\left(2y\right)^2\) \(=\left(5x-2y\right)^2\)

i) \(25x^4-10x^2y+y^2=\left(5x^2\right)^2-2.5x^2.y+y^2=\left(5x^2-y\right)^2\)

22 tháng 8 2016

cần gấp nhé. sắp đi học rồi

22 tháng 8 2016

có ai giúp ko tick cho