How do models you factor linear expressions

If we model certain expression or equation, we mean to say that we are drawing them into some Cartesian plane or other forms of plane in order to clearly visualize them. Modeling the linear expressions, will allow you to see at which point are the lines most probably intersect. These points are then considered the factors. 

(x)=-3x^4+5x^3-8x^2-3x+2