设等比数例{an}的公比为d,因为a1+a3=10所以a1+a1d^2=10,a1(1+d^2)=10,因为a4+a6＝5/4,所以a1d^3+a1d^5=5/4,a1d^3(1+d^2)=5/4用a1(1+d^2)=10去除以a1d^3(1+d^2)=5/4得到1/d^3=8,解得d=1/2,代入a1(1+d^2)=10中得a1＝8,...