=a(a+2b)^3-[-b(a+2b)^3]
=(a+2b)^3(a+b)

êffeeffe

a/ \(4x^2-49=\left(2x\right)^2-7^2=\left(2x-7\right)\left(2x+7\right)\)

b/ \(a^2-2a-b^2-2b=\left(a^2-2a+1\right)-\left(b^2+2b+1\right)=\left(a-1\right)^2-\left(b+1\right)^2\)

\(=\left(a-1-b-1\right)\left(a-1+b+1\right)=\left(a-b-2\right)\left(a+b\right)\)

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

= x\(^2\)-ax-bx+ab

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

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

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

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

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

\(a,=\left(x+y\right)^2-5^2=\left(x+y+5\right)\left(x+y-5\right)\)

\(b,=\left(a-1\right)^2-1-\left(2b+1\right)^2-1=\)

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

a,( x² + 2xy + y² ) -25

=( x + y )² - 5²

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

b, 

\(9a^2-6ab+b^2-1=\left(3a-b\right)^2-1^2=\left(3a-b-1\right)\left(3a-b+1\right)\)

9a^2 - 6ab + b^2 - 1= (3a)^2 - 2.3a.b + b^2 -1

                            = (3a - b)^2 - 1^2

                            = (3a - b - 1).(3a - b + 1)

  9a² - 6ab + b² - 1 = (3a - b)² - 1

                                   =  (3a - b + 1)(3a-b-1)

b: \(4m^2n-8m^2n-12n\)

\(=-4m^2n-12n\)

\(=-4n\left(m^2+3\right)\)

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

d: \(16b^4-9c^2\)

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

e: \(5a\left(x+y\right)+x+y=\left(x+y\right)\left(5a+1\right)\)

a² + 2ab + b² - ac - bc

= (a+b)² -c(a+b)

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

Ta có

a,    x²-x-y²-y

=x²-y²-(x+y)

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

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

b,   x²-2xy+y²-z²

=(x-y)²-z²

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

con bai 32, 33 neu ban tra loi duoc minh h them

nhanh nha