1 + \(\dfrac{1}{3}\) +\(\dfrac{1}{6}\)+\(\dfrac{1}{10}\) +......+
\(\dfrac{2}{x(x+1)}\) =1\(\dfrac{1989}{1991}\)
\(\dfrac{help}{me}\)
1 + \(\dfrac{1}{3}\) + \(\dfrac{1}{6}\) + \(\dfrac{1}{10}\)
+......+ \(\dfrac{2}{x(x+1)}\) =1\(\dfrac{1989}{1991}\)
HeLp me
\(\dfrac{2}{1²}\) . \(\dfrac{6}{2²}\) . \(\dfrac{12}{3³}\) . \(\dfrac{20}{4²}\) +....+ \(\dfrac{110}{10²}\) . x = -20
Help me
Tính giá trị biểu thức \(A=x^2-3x+1\) khi \(\left|x+\dfrac{1}{3}\right|=\dfrac{2}{3}\)
Help me
Tìm cặp số nguyên (x,y) biết
\(\dfrac{x-1}{9}\) + \(\dfrac{1}{3}\) = \(\dfrac{1}{y+2}\)
(Điều kiện y ≠ -2)
Help me Nguyễn Đức Trí.........
\(\dfrac{1}{5}\).\(\left(x+\dfrac{1}{5}\right)\)\(+\)\(\dfrac{2}{5}\)\(\left(x+\dfrac{5}{3}\right)\)\(=\)\(\dfrac{98}{75}\)
help me please :D
Cho A = \(\dfrac{1}{2}\) + \(\dfrac{1}{2^{2}}\)+ \(\dfrac{1}{2^{3}}\)+ \(\dfrac{1}{2^{4}}\) + ...+ \(\dfrac{1}{2^{10}}\)
Chứng tỏ rằng A + \(\dfrac{1}{2^{10}}\)= 1
Calculate: \dfrac{1}{10} +\dfrac{2}{10} +\dfrac{3}{10} +\dfrac{4}{10} +\dfrac{5}{10} +\dfrac{6}{10} +\dfrac{7}{10} +\dfrac{8}{10} +\dfrac{9}{10} +\dfrac{55}{10}=101+102+103+104+105+106+107+108+109+1055=
Help me please !
Tính hợp lý
\(A= (\dfrac{92-\dfrac{1}{9}-\dfrac{2}{10}-\dfrac{3}{11}-...-\dfrac{91}{99}-\dfrac{92}{100}}{\dfrac{1}{45}+\dfrac{1}{50}+\dfrac{1}{55}+...+\dfrac{1}{495}+\dfrac{1}{500}}\) B= \(\dfrac{\dfrac{1}{2}+\dfrac{1}{3}+\dfrac{1}{4}+...+\dfrac{1}{8}+\dfrac{1}{9}+\dfrac{1}{10}}{\dfrac{1}{9}+\dfrac{2}{8}+\dfrac{3}{7}+...+\dfrac{8}{2}+\dfrac{9}{1}})\)