a)\(x^3+2x^2+x=x\left(x^2+2x+1\right)=x\left(x+1\right)^2\)
b)\(x^2-2xy+y^2-9=\left(x^2-2xy+y^2\right)-3^2\)
\(=\left(x-y\right)^2-3^2=\left(x-y+3\right)\left(x-y-3\right)\)
a.x3 + 2x2 + x= x3 +x2 + x2 + x = ( x3 + x2 ) + ( x2+ x )
=x(x2+x) + (x2+x)
=(x+1)*(x2+x)
b.x2 - 2xy + y2 - 9= ( x2 - 2xy + y2 ) - 32
=( x - y )2 - 32
=( x - y - 3 )*( x - y + 3 )