A=1/1.2+1/3.4+1/5.6+...+1/49.50. Chứng minh A<1
a=1/1.2+1/3.4+1/5.6+....+1/49.50<1 chứng minh rằng a<1
Chứng minh rằng:
a) 1.2 - 1 phần 2! + 2.3 -1 phần 3! + 3.4 -1/4! + ... + 99.100 -1 /100! < 2
b) 1/1.2 + 1/3.4 + 1/5.6 + ... + 1/49.50 = 1/26 + 1/27 + 1/28 + ... + 1/50
cho A = 1/1.2+1/2.3+1/3.4+...+1/49.50 ; cho B = 1.2+1.3+3.4+....+49.50
tính 50mủ 2A - B/17
Cho A=(1/1.2+1/3.4+1/5.6+...+1/67.68).35.36....67.68. Chứng minh A chia hết cho 69
CMR : \(\frac{1}{1.2}+\frac{1}{3.4}+\frac{1}{5.6}+...+\frac{1}{49.50} =\frac{1}{26}+\frac{1}{27}+...+\frac{1}{49}+\frac{1}{50}\)
1/1.2+1/3.4+1/5.6+...+1/49.50 so sánh với 1
\(CMR:\) \(\frac{1}{1.2}+\frac{1}{3.4}+\frac{1}{5.6}+...+\frac{1}{49.50}=\frac{1}{26}+\frac{1}{27}+\frac{1}{28}+...+\frac{1}{50}\)
chứng minh răng A chia hết cho 97 biết A=(1/1.2+1/3.4+1/5.6+....+1/63.64).33.34.35.....64
