Question

How to simplify (1-p)(1+p+p^2+p^3+p^4+p^5+p^6)?

Answer 1

Use FOIL
(1-p)(1+p+p^2+p^3+p^4+p^5+p^6)
1+p+p^2+p^3+p^4+p^5+p^6 -1p - p^2 - p^3 - p^4 - p^5 - p^6
1 + p -1p <------------------Answer