Question

A=1/2+ 1/6+1/12+...+1/132

B= 5/1.4+ 5/4.7+5/7.10+...+5/97.100

Answer 1

\(A=\frac{1}{2}+\frac{1}{6}+\frac{1}{12}+...+\)\(\frac{1}{132}\)= \(\frac{1}{1\cdot2}+\frac{1}{2\cdot3}+\frac{1}{3\cdot4}+...+\frac{1}{11\cdot12}\)

\(=\frac{1}{1}-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+...+\frac{1}{11}-\frac{1}{12}\)\(=1-\frac{1}{12}=\frac{11}{12}\)

Answer 2

giải hộ mình bài về công nhân với

Answer 3

B = 5/1.4 + 5/4.7 + 5/7.10 + ... + 5/97.100

B = 5/3.(3/1.4 + 3/4.7 + 3/7.10 + ... + 3/97.100)

B = 5/3.(1 - 1/4 +1/4 -1/7 +1/7 - 1/10 + ... + 1/97 - 1/100)

B = 5/3.(1 - 1/100)

B = 5/3.99/100

B = 33/20

Answer 4

B = 5/1.4 + 5/4.7 + 5/7.10 + ... + 5/97.100

B = 5/3.(3/1.4 + 3/4.7 + 3/7.10 + ... + 3/97.100)

B = 5/3.(1 - 1/4 +1/4 -1/7 +1/7 - 1/10 + ... + 1/97 - 1/100)

B = 5/3.(1 - 1/100)

B = 5/3.99/100

B = 33/20