A = 1.3 + 3.5 |+ 5.7 + ... + 97.99
6A = 1.3.6 + 3.5.(7-1) + 5.7.(9-3) + ... + 97.99.(101-95)
6A = 1.3.6 + 3.5.7 - 1.3.5 + 5.7.9 - 3.5.7 + ... + 97.99.101 - 95.97.99
6A = 1.3.6 + 97.99.101 - 1.3.5
6A = 3.(1 + 97.33.101)
2A = 1 + 323301 = 323302
A = 161651
Bài tập: Tính tổng
A = 1.3 + 3.5 + 5.7 + …+ 97.99 + 99.101.
B=1.3+2.4+3.5+4.6+...+99.101+100.102
C=1.3.5+3.5.7+...+95.97.99
Giúp mik vs ạ. Giải chi tiết ra mik sẽ tik cho. Cho mik cảm ơn trước!!! 
CHO A=\(\dfrac{2}{1.3}+\dfrac{2}{3.5}+\dfrac{2}{5.7}+\dfrac{2}{7.9}+.....+\dfrac{2}{97.99}\)
Tính A 
P=1.3+2.4+3.5+...+97.99+98.100
Tính tổng
a) \(\dfrac{2}{1.3}\)+ \(\dfrac{2}{3.5}\)+ \(\dfrac{2}{5.7}\)+......+\(\dfrac{2}{99.101}\)
b) \(\dfrac{2}{1.3}\)+ \(\dfrac{5}{3.5}\)+ \(\dfrac{5}{5.7}\)+.......+ \(\dfrac{5}{99.101}\)
a) A = 1.3 + 2.4 + 3.5 +...+ 97.99 + 98.100
b) B = 1.2.3 + 2.3.4 + 3.4.5 +...+ 48.49.50
c) C = 1/2 + 1/2^2 + 1/2^3 +...+ 1/2^10
Bài 1:Tính tổng
a) \(\dfrac{2}{1.3}\) + \(\dfrac{2}{3.5}\) + \(\dfrac{2}{5.7}\) +......+\(\dfrac{2}{99.101}\)
b)\(\dfrac{5}{1.3}\) + \(\dfrac{5}{3.5}\) + \(\dfrac{5}{5.7}\) +.......+\(\dfrac{5}{99.101}\)
Dấu chấm là dấu nhân nhé các bạn.
1,Tính tổng:a,\(\frac{2}{1.3}\)+\(\frac{2}{3.5}\)+\(\frac{2}{5.7}\)+....+\(\frac{2}{99.101}\)
b,\(\frac{5}{1.3}\)+\(\frac{5}{3.5}\)+\(\frac{5}{5.7}\)+....+\(\frac{5}{99.101}\)
\(\dfrac{5}{1.3}+\dfrac{5}{3.5}+\dfrac{5}{5.7}+......+\dfrac{5}{99.101}\)
Ai pk làm giúp vs ạ!!!!
\(M=\dfrac{2}{3.5}+\dfrac{2}{5.7}+\dfrac{2}{7.9}+...+\dfrac{2}{97.99}\)
Giúp mình với
