− z 6 a 10 − 6 z 4 a 10 − 10 z 2 a 10 − 4 a 10 + z 8 a 8 + 8 z 6 a 8 + 21 z 4 a 8 + 20 z 2 a 8 + 5 a 8 {\displaystyle -z^{6}a^{10}-6z^{4}a^{10}-10z^{2}a^{10}-4a^{10}+z^{8}a^{8}+8z^{6}a^{8}+21z^{4}a^{8}+20z^{2}a^{8}+5a^{8}}