\(1,8x^3+12x^2y+6xy^2+y^3=\left(2x+y\right)^3\\ 3,x^2-x-y^2-y=\left(x^2-y^2\right)-\left(x+y\right)\\ =\left(x-y\right)\left(x+y\right)-\left(x+y\right)\\ =\left(x+y\right)\left(x-y-1\right)\\ 4,x^2-2xy+y^2-z^2=\left(x-y\right)^2-z^2\\ =\left(x-y-z\right)\left(x-y+z\right)\\ 5,x^2-3x+xy-3y=x\left(x-3\right)+y\left(x-3\right)\\ =\left(x-3\right)\left(x+y\right)\)
\(a,8x^3+12x^2y+6xy^2+y^3=\left(2x+y\right)^3\)
b, đề thiếu nhé
\(c,x^2-x-y^2-y=\left(x^2-y^2\right)-\left(x+y\right)\)
\(=\left(x-y\right)\left(x+y\right)-\left(x+y\right)\)
\(=\left(x+y\right)\left(x-y-1\right)\)
\(d,x^2-2xy+y^2-z^2=\left(x+y\right)^2-z^2\)
\(=\left(x+y-z\right)\left(x+y+z\right)\)
\(e,x^2-3x+xy-3y=\left(x^2-3x\right)+\left(xy-3y\right)\)
\(=x\left(x-3\right)+y\left(x-3\right)\)
\(=\left(x+y\right)\left(x-3\right)\)
câu g hình như sai đề rồi đó ❤ NTN ❤
Khôi Bùi Ông hok rồi ông giúp tui câu b và g cái coi 
\(b,\left(xy+1\right)^2-\left(x-y\right)^2=x^2y^2-2xy+1-\left(x^2-2xy+y^2\right)\)
\(=x^2y^2-2xy+1-x^2+2xy-y^2\)
\(=x^2y^2-x^2-y^2+1\)
sửa đề câu g:
\(2xy+3z+6y+xz=\left(2xy+xz\right)+\left(3z+6y\right)\)
\(=x\left(2y+z\right)+3\left(2y+z\right)\)
\(=\left(x+3\right)\left(2y+z\right)\)
