\(\left(x+1\right)^4+\left(x^2+x+1\right)^2\)
\(=\left(x+1\right)^4+x^2\cdot\left(x+1\right)^2+2x\left(x+1\right)+1\)
\(=\left(x+1\right)^2\cdot\left[\left(x+1\right)^2+x^2\right]+2x^2+2x+1\)
\(=\left(2x^2+2x+1\right)\left(x^2+2x+1+1\right)\)
\(=\left(2x^2+2x+1\right)\left(x^2+2x+2\right)\)