1. ## Polynomial

How to solve this in simple way ...?

What is the value of x ?
x3 + x2 + x + 1 = 0

2. ## Re: Polynomial

Yes you can factorise by grouping...

\displaystyle \begin{align*} x^3 + x^2 + x + 1 &= 0 \\ x^3 + x + x^2 + 1 &= 0 \\ x\left( x^2 + 1 \right) + 1 \left( x^2 + 1 \right) &= 0 \\ \left( x^2 + 1 \right) \left( x + 1 \right) &= 0 \\ x^2 + 1 = 0 \textrm{ or } x + 1 &= 0 \end{align*}

The first equation doesn't have any real solutions (if you want complex solutions they're \displaystyle \begin{align*} x = \pm \mathrm{i }\end{align*}) and the second equation has solution x = -1.