... cac he so a2,b1,c2:";cin>>a2>>b2>>c2;d=dt(a1,b1,a2,b2);dx=dt(c1,b1,c2,b2);dy=dt(a1,c1,a2,c2);if(d!=0){ st.replace(i ,2, " ");}if(st[0]==' ') st.replace(0,1,"");n=st.size();if(st[n-1]==' ... namespace std; void main(){int f1,f2,f,n;f1=f2=1;cout<<"Nhap n=";cin>>n;if(n> ;2) {for(int i=0;i<n -2; i++){f=f1+f2;f1=f2;f2=f;}cout<<"so hang thu ... a1,b1,c1,a2,b2,c2,d,dx,dy;cout<<"Nhap lan luot cac he so a1,b1,c1:";cin>>a1>>b1>>c1;cout<<"Nhap lan luot cac he so a2,b1,c2:";cin>>a2>>b2>>c2;d=dt(a1,b1,a2,b2);dx=dt(c1,b1,c2,b2);dy=dt(a1,c1,a2,c2);if(d!=0){...