1.tính nhanh :(6/8+1).(6/18+1).(6/30+1)...(6/10700+1)
2.chứng minh rằng :A=1/2!+1/3!+1/4!+...+1/1000!
Tính nhanh E=\(\frac{6}{8+1}.\frac{6}{18+1}.\frac{6}{30+1}...\frac{6}{10700+1}\)
tính A biêt
A=(6/8+1)*(6/18+1)*(6/30+1)*...*(6/10700+1)
Tính (6/8+1)(6/18+1)(6/30+1)...(6/10700+1)
Tính nhanh:
F=\(\left(\frac{6}{8}+1\right)\left(\frac{6}{18}+1\right)\left(\frac{6}{30}+1\right).....\left(\frac{6}{10700}+1\right)\)
F=(6/8+1)(6/18+1)(6/30+1)...(6/10700+1)
14.24.36...10706
F= ---------------------------
8.18.30....10700
7.2.8.3.9.4...106.101
F= -----------------------------------
8.1.9.2.10.3...107.100
(7.8.9....106)(2.3.4...101)
F= ----------------------------------------
(8.9.10...107)(2.3.4...100)
7.101
F= ----------
107
F=1
Mình nhầm nhé! Bạn để nguyên:
F =707/101 là được rồi
K mình nhé!
(6/8+1)(6/18+1)(6/30+1)...(6/10700+1)=?
B=(6/8+1)(6/18+1)(6/30)...(6/10700+1)
B=(6/8+1)(6/18+1)(6/30+1)...(6/10700+1)
a.A=1 1/2 x 1 1/3 x 1 1/4 x 1 1/5 x...x1 1/2020 x 1 1/2021
b.B=1 1/2 + 1 1/6 + 1 1/12 +1 1/20+ ... + 1 1/380 + 1 1/420
c.C=1 6/8 x 1 6/18 x 1 6/30 x 1 6/44 x ... x 1 6/10700
a.A=1 1/2 x 1 1/3 x 1 1/4 x 1 1/5 x...x1 1/2020 x 1 1/2021
b.B=1 1/2 + 1 1/6 + 1 1/12 +1 1/20+ ... + 1 1/380 + 1 1/420
c.C=1 6/8 x 1 6/18 x 1 6/30 x 1 6/44 x ... x 1 6/10700