@ all 1st thanks for trying to help me 2nd sorry for late in my reply i wanna an easy and quickly method that i can use to solve equation of order 6, 5 and 4 and i don't wanna the solution for 6 order equation that i post in the head of the topic. this equation for example only @gamehead200, Why you Diff. (d/ds) HOw it can help? Regards, Xtremee