a) \(A=x^3+2x^2y+xy^2\)
\(A=x\left(x^2+2xy+y^2\right)\)
\(A=x\left(x+y\right)^2\)
b) \(B=x^2-14x+49\)
\(B=\left(x-7\right)^2\)
c) \(C=4x^2-1\)
\(C=\left(2x-1\right)\left(2x+1\right)\)
d) \(D=x^3+27\)
\(C=\left(x+3\right)\left(x^2-3x+9\right)\)