Tính \(Q=\dfrac{1+\dfrac{1}{3}+\dfrac{1}{5}+...............+\dfrac{1}{99}}{\dfrac{1}{1.99}+\dfrac{1}{3.97}+\dfrac{1}{5.95}+.............+\dfrac{1}{97.3}+\dfrac{1}{99.1}}\)
Tính \(H=\dfrac{\dfrac{1}{99}+\dfrac{2}{98}+\dfrac{3}{97}+...........+\dfrac{99}{1}}{\dfrac{1}{2}+\dfrac{1}{3}+\dfrac{1}{4}+.............+\dfrac{1}{100}}:\dfrac{92-\dfrac{1}{9}-\dfrac{1}{10}-..............\dfrac{92}{100}}{\dfrac{1}{45}+\dfrac{1}{50}+\dfrac{1}{55}+........+\dfrac{1}{500}}\)
Help me!!!
Cho A = 1+2-3-4+5+6-....-99-100
help me !!!!!!!
Cho \(M=\dfrac{1}{1+2+3}+\dfrac{1}{1+2+3+4}+...................+\dfrac{1}{1+2+3+...........+59}\)
Chứng minh \(M< \dfrac{2}{3}\)
Help me!!!!!!!!!!!!!!
Cho A = \(\dfrac{1}{41}+\dfrac{1}{42}+\dfrac{1}{43}+\dfrac{1}{44}+......+\dfrac{1}{80}\)
Chứng tỏ \(\dfrac{7}{12}< A< \dfrac{5}{6}\)
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SOS ! Help me
1. 1+ (-2) + 3+ (-4) + . . . +19 + (-20)
2. 1 - 2 + 3- 4 + . . . + 99 - 100
3. -1 + 3 -5 + 7 - . . . +97 - 99
4. 1+ 2 - 3+ 4 + . . . +97 + 98 - 99 - 100
Rút gọn \(C=\dfrac{1}{3}+\dfrac{1}{3^3}+\dfrac{1}{3^5}+...+\dfrac{1}{3^{99}}+\dfrac{1}{8.3^{99}}\)
tính giá trị biểu thức sau
A= -1 -2 +3 +4 -5 -6 +7 +8-9-10+11+12 -...........-2013-2014+2015+2016
B= [\(\dfrac{1}{2}\) -1 ] : [\(\dfrac{1}{3}\) -1] : ...................: [\(\dfrac{1}{99}\) -1} : [\(\dfrac{1}{100}\) -1]
tính
1+1/3+1/5+1/7+...+1/99