p^2 - 2pq - q^2
eterozigoti= 2 pq
da cui:
2pq = 8 q^2
risolviamo e:
2pq/q^2 = 8
2p/q
2p=8q
ma p=1 - q quindi
2(1-q)=8q
2 - 2q = 8q
2 = 10 q
q= 2/10
q=0.2