New oscillation criteria for second order linear difference equations with positive and negative coefficients

The oscillation of second order neutral difference equations with positive and negative coefficients of the form 2.xn C anxn􀀀 / C pnxn􀀀 􀀀 qnxn􀀀 D 0; D 1 is investigated.Weobtain many new results using the comparison between both first order and second order difference equations. An example is given to show the strength of the obtained results.