a) =y^2-(x+3)^2
=(y-x-3)(y+x+3).
b)
=x^2-(y^2+2y+1)
=x^2-(y+1)^2
=(x-y-1)(x+y+1)
c)
=(5x^2-15x)(xy-2y)
=5x(x-3)y(x-2)
=5xy(x-2)(x-3).
a) ta có \(y^2-\left(x+3\right)^2=\left(y-x-3\right)\left(y+x+3\right)\)
b) \(x^2-\left(y+1\right)^2=\left(x-y-1\right)\left(x+y+1\right)\)
c) \(\left(xy-2y\right)\left(5x^2-15x\right)=y\left(x-2\right)5x\left(x-3\right)=5xy\left(x-2\right)\left(x-3\right)\)