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25 tháng 8 2018

a^2-25-2ab+b^2

= (a^2 - 2ab + b^2 ) - 5^2

= (a -b)^2 - 5^2 = ( a - b - 5 ) ( a - b + 5 )

5x^2-6xy+y^2

= (3x)^2 - 2.3x.y + y^2 - (2x)^2

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

= ( 3x - y - 2x ) ( 3x - y + 2x ) = ( x - y) ( 5x - y )

2x^3-8x^2+8x

= 2x^3 - 4x^2 - 4x^2 + 8x

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

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

= 2x(x-2)(x-2) = 2x .(x-2)^2

5x-5y-3x^2+6xy-3y^2

=5(x - y) - 3(x^2 - 2xy + y^2 )

= 5(x-y) - 3(x-y)^2 = (x-y)[ 5 - 3(x-y) ]

4x^4-9x^2

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

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

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

25 tháng 8 2018

a) \(a^2-25-2ab+b^2\)

\(=\left(a-b\right)^2-25\)

\(=\left(a-b-5\right)\left(a-b+5\right)\)

b) \(5x^2-6xy+y^2\)

\(=\left(3x\right)^2-2.3x.y+y^2-\left(2x\right)^2\)

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

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

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

c) \(2x^3-8x^2+8x\)

\(=2x^3-4x^2-4x^2+8x\)

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

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

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

d) \(5x-5y-3x^2+6xy-3y^2\)

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

\(=5\left(x-y\right)-3\left(x-y\right)^2\)

\(=\left(x-y\right)\left[5-3\left(x-y\right)\right]\)

e) \(4x^4-9x^2\)

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

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

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

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

f) \(x^8+4\)

\(=\left(x^4\right)^2+2.x^4.2+2^2-2.x^4.2\)

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

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

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

i) \(4x^2-y^2+4x+1\)

\(=\left(2x\right)^2+2.2x+1-y^2\)

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

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

j) \(3x^2-7x+10\)

\(=3\left(x^2-\dfrac{7}{3}x+\dfrac{10}{3}\right)\)

\(=3\left(x^2-2.x.\dfrac{7}{6}+\dfrac{49}{36}-\dfrac{49}{36}+\dfrac{10}{3}\right)\)

\(=3\left[\left(x-\dfrac{7}{6}\right)^2+\dfrac{71}{36}\right]\)

g) \(x^5+x+1\)

\(=x^5+x^4+x^3-x^4-x^3-x^2+x^2+x+1\)

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

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

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

h) \(x^4+2019x^2+2018x+2019\)

\(=\left(x^4-x\right)+\left(2019x^2+2019x+2019\right)\)

\(=x\left(x^3-1\right)+2019\left(x^2+x+1\right)\)

\(=x\left(x-1\right)\left(x^2+x+1\right)+2019\left(x^2+x+1\right)\)

\(=\left(x^2+x+1\right)\left[x\left(x-1\right)+2019\right]\)

\(=\left(x^2+x+1\right)\left(x^2-x+2019\right)\)

17 tháng 8 2019

4x4 - 9x2

= 4x2 . x2 - 9x2 

= (4x- 9)x2

Ko chắc đâu bạn ak!

17 tháng 8 2019

\(4x^4-9x^2\)

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

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

17 tháng 8 2016

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

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

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

6 tháng 4 2020

\(a.\left(8x^4-4x^3+x^2\right):2x^2=4x^2-2x+\frac{1}{2}\)

\(b.\left(2x^4-x^3+3x^2\right):\left(-\frac{1}{3x^2}\right)=-6x^6+3x^5-9x^4\)

\(c.\left(-18x^3y^5+12x^2y^2-6xy^3\right):6xy=-3x^2y^4+2xy-y^2\)

\(d.\left(\frac{3}{4x^3y^6}+\frac{6}{5x^4y^5}-\frac{9}{10x^5y}\right):-\frac{3}{5x^3y}=-\frac{5}{4y^5}-\frac{2}{xy^4}-\frac{3}{2x^2}\)

6 tháng 4 2020

Thank you

19 tháng 6 2015

b)x2+2xy+y2-16=(x+y)2-42=(x+y+4)(x+y-4)

c)3x2+5x-3xy-5y=x(3x+5)-y(3x+5)=(3x+5)(x-y)

d)4x2-6x3y-2x2+8x=2x(2x-3x2y-x+4)

e)x2-4-2xy+y2=(x2-2xy+y2)-4=(x-y)2-22=(x-y-2)(x-y+2)

k)x2-y2-z2-2yz=x2-(y+z)2=(x-y-z)(x+y+z)

m)6xy+5x-5y-3x2-3y2=3(x2-2xy+y2)+5(x-y)=3(x-y)2+5(x-y)=(x-y)(3x-3y+5)


 

27 tháng 6 2016

b. (x^2+2xy+y^2)-16 =(x+y)^2-16=(x+y+4)(x+y-4)

23 tháng 8 2016

ngất

23 tháng 8 2016

vào bệnh viện hoặc đến nơi khám chữa bệnh gần nhà nhất ko kịp thì die

15 tháng 7 2016

a)x^2-(a+b)x+ab

= x^2 - ax - bx + ab

= (x^2 - ax) - (bx - ab)

= x(x-a) - b(x-a)

= (x-b)(x-a) 

b)7x^3-3xyz-21x^2+9z

c)4x+4y-x^2(x+y)

= 4(x + y) - x^2(x+y)

= (4-x^2) (x+y)

= (2-x)(2+x)(x+y)

d) y^2+y-x^2+x

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

= (y-x)(y+x)+ (x+y)

= (y-x+1) (x+y)

e)4x^2-2x-y^2-y

= [(2x)^2 - y^2] - (2x +y)

= (2x-y)(2x+y) - (2x+y)

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

f)9x^2-25y^2-6x+10y

31 tháng 8 2021

ko biết làm

 

16 tháng 12 2018

\(10x\left(x-y\right)-6y\left(y-x\right)\)

\(=10x\left(x-y\right)+6x\left(x-y\right)\)

\(=\left(10x+6x\right)\left(x-y\right)\)

\(c,3x^2+5y-3xy-5x\)

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

\(=3x\left(x-y\right)-5\left(x-y\right)\)

\(=\left(3x-5\right)\left(x-y\right)\)

\(e,27+27x+9x^2=3\left(9+9x+x^2\right)\)

16 tháng 12 2018

\(f,8x^3-12x^2y+6xy^2-y^3\)

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

\(g,x^3+8y^3=x^3+\left(2y\right)^3\)

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

\(i,x^2-25-2xy+y^2\)

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

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