Tính
E=(169-4^2).(169-5^2).(169-6^2).(169-7^2).(169-8^2).(169-9^20).(169-10^2).(169-11^2).(169-12^2).(169-13^2)
tinh nhanh dau cham la nhan
(169-4^2).(169-5^2).....(169-13^2)
tinh nhanh
S= -(169-1^2).(169-2^2)......(169-100^2)
(54+47).(89-27).(24-42)
(169-42).(169-52)......(169-132)
(169-42)(169-52)(169-62)..............(169-142)(169-152)
tinh B
B=81.[12-12/7-12/289-12/85/4-4/7-4/289-4/85:5+5/13=5/169+5/91/6+6/13+6/169+6/91].158158158/711711711
Tính : (169 - 4^2) . (169 - 5^2) ... (169 - 13^2)
(169 - 4 mũ 2) (169 -5 mũ 2) ...( 169 - 13 mũ 2)
(169-42):(169-52...169-132) = ?