mình chỉ biết câu b thôi:
Ta biến đổi vế phải :
1-1/2+1/3-1/4+.....+1/49-1/50
=(1+1/3+1/5+....+1/49)-(1/2+1/4+1/6+.......+1/50)
=(1+1/2+1/3+.....+1/49+1/50)-2(1/2+1/4+1/6+......+1/50)
=(1+1/2+...+1/50)-(1+1/2+1/3+....+1/25)
=1/26+1/27+.......+1/50
Vậy 1/26+1/27+1/28+.....+1/50=1-1/2+1/3-1/4+......+1/49-1/50
Chứng Minh Rằng :1/26+1/27+1/28+...+1/50=1-1/2+1/3-1/4+...+1/49-1/50
Chứng minh rằng: 1/26+1/27+1/28+...+1/50=1-1/2+1/3+1/4+...+1/49-1/50
Chứng minh rằng : 1/26+1/27+1/28+.......+1/50=1-1/2+1/3-1/4+.....+1/49-
1/50
Chứng minh rằng:
1/26+1/27+1/28+...+1/50=1-1/2+1/3-1/4+...+1/49-1/50
chứng tỏ
1/26 + 1/27 + 1/28 + ... + 1/50 =1 - 1/2 + 1/3 - 1/4 + .... + 1/49 - 1/50
Chứng minh rằng :
\(\frac{1}{26}+\frac{1}{27}+\frac{1}{28}+....+\frac{1}{49}+\frac{1}{50}=1-\frac{1}{2}+\frac{1}{3}-\frac{1}{4}+....+\frac{1}{49}-\frac{1}{50}\)
Chứng minh:
\(\frac{1}{26}+\frac{1}{27}+\frac{1}{28}+...+\frac{1}{49}+\frac{1}{50}=1-\frac{1}{2}+\frac{1}{3}-\frac{1}{4}+...+\frac{1}{49}-\frac{1}{50}\)
Chứng minh 1/2+1/3×4+1/5×6+...+1/49×50=1/26+1/27+....+1/50
Chứng minh rằng
\(\frac{1}{26}+\frac{1}{27}+\frac{1}{28}+...+\frac{1}{50}=1-\frac{1}{2}+\frac{1}{3}-\frac{1}{4}+...+\frac{1}{49}-\frac{1}{50}\)
