1. = 2(a+b)

2. =2(a-b)

3.=2(a+2b-3c)

4.=3(a-2b-3c)

5.=-4(a+2b+3c)

6.=-5(x+2xy+3y)

7.=-7(a+2ab+3b)

8.=6(xy-2x-3y)

9.=8(xy-3y+2x)

10.=9(ab-2a+1)

Lần sau bn cần ghi đề rõ ràng hơn

11.=x(y-1)

12.=a(x+1)

13.=m(x+y+1)

14.=-a(x+y+1)

15.=-a(x²+x+1)

16.=-2a(x+2y)

17.=2a(x-y+1)

18.=2(2ax-ay-2)

19.=5a(1-2x-3)

20.=-2ab(a+2b+3)

1, 2a+2b = 2( a + b )

2, 2a-2b = 2( a - b )

3, 2a+4b-6c = 2( a + 2b - 3c )

4, 3a-6b-9c = 3( a - 2b - 3c )

5, xy-x = x( y - 1 )

6, -5x-10xy-15y = -5( x + 2xy + 3y )

7, -7a-14ab-21b = -7( a + 2ab + 3b )

8, 6xy-12x-18y = 6 ( xy - 2x - 3y )

9, 8xy-24y+16x = 8 ( xy - 3y + 2x )

10, 9ab-18a+9 = 9( ab - 2a + 1 )

11, ax+a = a( x + 1 )

12, mx+my+m = m( x + y + 1 )

13, -ax-ay-a = -a( x + y +1 )

14, -2ax-4ay = -2a( x + 2y )

15, 2ax-2ay+2a = 2a( x - y + 1 )

16, 4ax-2ay-2 = 2( 2ax - a - 1 )

17, 5a-10ax-15a = 5a( 1 - 2x - 3 ) = 5a( -2x - 2 )

18, 5ax-15ay+20a = 5a( x - 3y + 4 )

19, 3a²x-6a²y+12a = 3a( ax - 2ay + 4 )

20, 2axy-4a²xy²+6a³x\(^2\) = 2ax( y - 2ay\(^2\) + 3a\(^2\)x )

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

2) 4a^2 - 4b^2 - 4a + 1 = ( 4a^2 - 4a +1) - 4b^2 = (2a-1)^2 - 4b^2 = (2a-1-2b)(2a-1+2b)

3) a^3+6a^2+12a+8= (a^3+8)+(6a^2+12a)= (a+2)(a^2-2a+4)+6a(a+2)=(a+2)(a^2-2a+4+6a)=(a+2)(a^2+4a+4)=(a+2)(a+2)^2=(a+2)^3

a) ax - 2x - a² + 2a

= ( ax - 2x ) - ( a² - 2a )

= x ( a - 2 ) - a ( a - 2 )

= ( a - 2 ) ( x - a )

b) x² + x - ax - a

= ( x² + x ) - ( ax + a )

= x ( x + 1 ) - a ( x + 1 )

= ( x + 1 ) ( x - a )

Hok Tốt!!!

a) ax -2x- a²+ 2a

= (ax -2x ) -(a² -2a )

= x(a-2) -a ( a-2 )

= (x-a) (a-2)

b) x² +x -ax -a

=( x² +x ) - ( ax +a )

= x( x+1 ) -a ( x+1 )

= ( x-a ) (x+ 1)

c) 2x² +4ax +x +2a

=( 2x² + 4ax )  + ( x+ 2a )

= 2x ( x+ 2a ) + ( x+2a )

= ( 2x +1 ) (x+2a )

d) 2xy -ax +x² - 2ay

= (2xy -2ay ) + (  -ax + x² )

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

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

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

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

c) \(\dfrac{1}{4}a^2-\dfrac{9}{25}=\left(\dfrac{1}{2}a-\dfrac{3}{5}\right)\left(\dfrac{1}{2}a+\dfrac{3}{5}\right)\)

d) \(\dfrac{9}{4}a^4-\dfrac{16}{25}=\left(\dfrac{3}{2}a^2-\dfrac{4}{5}\right)\left(\dfrac{3}{2}a^2+\dfrac{4}{5}\right)\)

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

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

a/ $25x^2-1\\=(5x)^2-1^2\\=(5x-1)(5x+1)$

b/ $a^2-9\\=a^2-3^2\\=(a-3)(a+3)$

c/ $\dfrac{1}{4}a^2-\dfrac{9}{25}\\=\left(\dfrac{1}{2}a\right)^2-\left(\dfrac{3}{5}\right)^2\\=\left(\dfrac{1}{2}a-\dfrac{3}{5}\right)\left(\dfrac{1}{2}a+\dfrac{3}{5}\right)$

d/ $\dfrac{9}{4}a^4-\dfrac{16}{25}\\=\left(\dfrac{3}{2}a^2\right)^2-\left(\dfrac{4}{5}\right)^2\\=\left(\dfrac{3}{2}a^2-\dfrac{4}{5}\right)\left(\dfrac{3}{2}a^2+\dfrac{4}{5}\right)\\=\left[\left(\sqrt{\dfrac 3 2}a\right)^2-\left(\dfrac{2\sqrt 5}{5}\right)^2\right]\left(\dfrac{3}{2}a^2+\dfrac{4}{5}\right)\\=\left(\sqrt{\dfrac 3 2}a-\dfrac{2\sqrt 5}{5}\right)\left(\sqrt{\dfrac 3 2}a+\dfrac{2\sqrt 5}{5}\right)\left(\dfrac{3}{2}a^2+\dfrac{4}{5}\right)$

e/ $(2a+b)^2-a^2\\=(2a+b-a)(2a+b+a)\\=(a+b)(3a+b)$

f/ $16(x-1)^2-25(x+y)^2\\=[4(x-1)]^2-[5(x-y)]^2\\=[4(x-1)-5(x-y)][4(x-1)+5(x-y)]\\=[4x-4-5x+5y][4x-4+5x-5y]\\=(-x+5y-4)(9x-5y-4)$

a) \(2a-4b=2\left(a-2b\right)\)

c) \(2ax-2ay+2a=2a\left(x-y+1\right)\)

e) \(3xy\left(x-4\right)-9x\left(4-x\right)=3x\left(x-4\right)\left(y+3\right)\)

b,d xem lại đề

b,d đúng mag bk

a) =2(a+b)

b) =2(a-2b)

c) =2(a+2b-3c)

d) =3(a-2b+3c)

e)= -4(a+2b+3c)

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

g) =-7(a+2ab+3b)

h) = 6(xy-2x-3y)

k) = 8(xy-3y+2x)

n)=9(ab-2a+1)

\(2x^2+4ax+x+2a\)

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

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