72*0.9*0.9+10.4列递式0.8*0.9*0.9*0.9+0.8*13=（0.9*0.9*0.9+13）*0.8=（0.072+13）*0.8不对哦哦0.8*90*0.9*0.9+0.8*13=（90*0.9*0.9+13）*0.8=（72.9+13）80.8