Tính (9,1 + 10,2 + 11,3 + ...+ 17,9) + 19 = (9,1 + 17,9). 9 : 2 + 19 = 121,5 + 19 = 140,5
Tính Mẫu = \(\frac{40}{42}.\frac{54}{56}.\frac{70}{72}.....\frac{2650}{2652}=\frac{\left(5.8\right).\left(6.9\right).\left(7.10\right)....\left(50.53\right)}{\left(6.7\right).\left(7.8\right).\left(8.9\right)....\left(51.52\right)}=\frac{\left(5.6.7...50\right).\left(8.9.10....53\right)}{\left(6.7.8...51\right).\left(7.8.9...52\right)}=\frac{5.53}{51.7}=\frac{265}{357}\)
Vậy \(P=\frac{140,5}{\frac{265}{357}}.\frac{265}{357}=140,5\)