2: x(x+1)+5(x+1)
=(x+1)(x+5)
3: x(x+3)-y(x+3)
=(x+3)(x-y)
1:
\(=4xy\cdot1-4xy\cdot2xy+4xy\cdot3x^2y^2\)
=4xy(1-2xy+3x^2y^2)
Bài 1:
\(4xy-8x^2y^2+12x^3y^3\)
\(=4xy\cdot1-4xy\cdot2xy+4xy\cdot3x^2y^2\)
\(=4xy\cdot\left(1-2xy+3x^2y^2\right)\)
Bài 2:
\(x\left(x+1\right)+5\left(x+1\right)\)
\(=\left(x+1\right)\left(x+5\right)\)
Bài 3:
\(x\left(x+3\right)-y\left(x+3\right)\)
\(=\left(x+3\right)\left(x-y\right)\)