(a+b)^7=a^7+7a^6b+21a^5b^2+35a^4b^3+35a^3b^4+21a^2b^5+7ab^6+b^7
(2m-3)^3=8m^3-36m^2+54m-27
(4k-1)^3=64k^3-48k^2+12k-1
