\(4x^4+4x^3+5x^2+2x+1\)
\(=\left(2x^2\right)^2+2.2x^2.x+x^2+4x^2+2x+1\)
\(=\left(2x^2+x\right)^2+2\left(2x^2+x\right)+1\)
\(=\left(2x^2+x+1\right)^2\)
\(x^4+6x^3+11x^2+6x+1\)
\(=\left(x^2\right)^2+2.x^2.3x+\left(3x\right)^2+2x^2+6x+1\)
\(=\left(x^2+3x\right)^2+2\left(x^2+3x\right)+1\)
\(=\left(x^2+3x+1\right)^2\)
Chúc bạn học tốt.