\(9a^3-13a+6=\left(9a^3-6a^2\right)+\left(6a^2-4a\right)-\left(9a-6\right)=3a^2\left(3a-2\right)+2a\left(3a-2\right)-3\left(3a-2\right)=\left(3a-2\right)\left(3a^2+2a-3\right)\)

\(x^4-4x^3+8x+3=\left(x^4+x^3\right)-\left(5x^3+5x^2\right)+\left(5x^2+5x\right)+\left(3x+3\right)=x^3\left(x+1\right)-5x^2\left(x+1\right)+5x\left(x+1\right)+3\left(x+1\right)=\left(x+1\right)\left(x^3-5x^2+5x+3\right)=\left(x+1\right)\left[\left(x^3-3x^2\right)-\left(2x^2-6x\right)-\left(x-3\right)\right]=\left(x+1\right)\left(x-3\right)\left(x^2-2x-1\right)\)

\(a^4-9a^3+81a-81\)

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

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

\(=\left(x^7+x^6+x^5-x^3-x^2\right)-\left(x^6+x^5+x^4-x^2-x\right)+\left(x^5+x^4+x^3-x-1\right)\)

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

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

ta có :

1)

\((x+2)(x+3)(x+4)(x+5)-24\\=[(x+2)(x+5)]\cdot[(x+3)(x+4)]-24\\=(x^2+7x+10)(x^2+7x+12)-24\)

Đặt \(x^2+7x+10=y\), khi đó biểu thức trở thành:

\(y(y+2)-24\\=y^2+2y-24\\=y^2+2y+1-25\\=(y+1)^2-5^2\\=(y+1-5)(y+1+5)\\=(y-4)(y+6)\\=(x^2+7x+10-4)(x^2+7x+10+6)\\=(x^2+7x+6)(x^2+7x+16)\)

2) Bạn xem lại đề!

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

\(=a\left(a-9\right)\left(a^2+1\right)\)

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

c) \(=x\left(2y+z\right)+3\left(2y+z\right)=\left(2y+z\right)\left(x+3\right)\)

d) \(=x^2-ax-bx+ab=x\left(x-a\right)-b\left(x-a\right)\)

\(=\left(x-a\right)\left(x-b\right)\)

a) = a(a³-9a²+a-9)

b) =3x²+5y-3xy-5x

= (3x²-5x)+(5y-3xy)

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

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

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

c)2xy +3z+6y+xz

=(2xy+6y)+(3z+xz)

=2y(x+3)+z(3+x)

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

a) \(a^4-9a^3+a^2-9a=a\left(a^3-9a^2+a-9\right)=a\left[\left(a^3-9a^2\right)+\left(a-9\right)\right]=a\left(a^2+1\right)\left(a-9\right)\)

\(=\left(x-1\right)\left(x-3\right)\)

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

\(=\left(x-3\right)\left(x-1\right)\)

\(64-x^2-y^2+2xy=64-\left(x^2-2xy+y^2\right)\)

\(=8^2-\left(x-y\right)^2=\left(8-x+y\right)\left(8+x-y\right)\)

−(x−y−8)(x−y+8)

=a⁴-81-(9a³-81a)

=(a²-9)(a²+9) -9a(a²-9)

=(a²-9)(a²-9a+9)

ĐẾN ĐÂY MÌNH CHỊU ,BẠN GIẢI TIẾP NHA