=> D + 49 = (1/49 + 1) + (2/48 + 1) +... (49/1 + 1)
= 50/1 + 50/2 + ... + 50/49
= 50(1/2+1/3+...+1/49) + 50
=> D = 50(1/2 + 1/3 +... + 1/49) + 1
= 50(1/2 + 1/3 +... + 1/49 + 1/50)
=> C/D = 1/50
a) 0,25-\(\dfrac{2}{3}\)+1\(\dfrac{1}{4}\)
b) \(\dfrac{3^2}{2}\):\(\dfrac{1}{4}\)+\(\dfrac{3}{4}\).2010
c) {[(\(\dfrac{1}{25}\)-0,6)2:\(\dfrac{49}{125}\)].\(\dfrac{5}{6}\)}-[(\(\dfrac{-1}{3}\))+\(\dfrac{1}{2}\)]
d) (-\(\dfrac{1}{2}\)-\(\dfrac{1^{ }}{3}\))2:[(\(\dfrac{-5}{36}\))-(\(\dfrac{-5}{36}\))0]
Mn giúp mk nhé mk gấp quá tí đi học ai làm được mk thả tim và like nhé
cho A= \(\dfrac{1}{2}\) + \(\dfrac{1}{3}\) + .............+ \(\dfrac{1}{50}\)
B= \(\dfrac{49}{1}\) + \(\dfrac{48}{2}\) + .....+ \(\dfrac{1}{49}\) = 50 * B
CMR A và B ko là số tự nhiên
C = \(\dfrac{-1}{4}-\dfrac{1}{4^2}-\dfrac{1}{4^3}-...-\dfrac{1}{4^{49}}\)
Câu 2: Chọn câu sai?
A.\(\dfrac{1}{3}=\dfrac{45}{135}\)
B.\(\dfrac{-13}{20}=\dfrac{26}{-40}\)
C. \(\dfrac{-4}{15}=\dfrac{-16}{-60}\)
D. \(\dfrac{6}{7}=\dfrac{-42}{-49}\)
Tính: \(A=\dfrac{3}{4}.\dfrac{8}{9}.\dfrac{15}{16}.\dfrac{24}{25}.\dfrac{35}{36}.\dfrac{48}{49}.\dfrac{63}{64}\)
\(a,\dfrac{-8}{5}:\left(1+\dfrac{2}{3}\right)\) \(b,\dfrac{7}{5}x\dfrac{15}{49}-\left(\dfrac{4}{5}+\dfrac{2}{3}\right):\dfrac{11}{5}\)
\(c,\dfrac{1}{3}:\left(\dfrac{2}{9}-\dfrac{7}{8}\right)\) \(d,\left(\dfrac{1}{6}-\dfrac{4}{5}\right):\dfrac{7}{5}\)
Giúp mik nha:>>
Tìm \(\dfrac{\left(\left(4\right)^{-2}:\left(\dfrac{1}{3}\right)^2\right)\dfrac{^1}{2}}{\left(-\dfrac{1}{6}\right)^2}\)
A. 36 B.27 C. 48 D.- 36 E.-27
thực hiện phép tính
\(\dfrac{16}{103}\)+(38+\(\dfrac{-16}{103}\))
\(\dfrac{100}{91}\)+310+\(\dfrac{-9}{91}\)
\(\dfrac{-13}{49}\)+(\(\dfrac{-36}{49}\)+41)
\(\dfrac{-10}{71}\):1\(\dfrac{4}{71}\)
\(\dfrac{4}{15}\)+\(\dfrac{8}{15}\):2 -\(\dfrac{1}{18}\).\(\left(-3\right)^2\)
CHo `M` `=` \(\dfrac{\left(\dfrac{3}{1\cdot4}+\dfrac{3}{2\cdot6}+\dfrac{3}{3\cdot8}+\dfrac{3}{4\cdot10}+...+\dfrac{3}{49\cdot100}\right)}{\left(1-\dfrac{1}{4}\right)\left(1-\dfrac{1}{5}\right)\left(1-\dfrac{1}{6}\right)\cdot\cdot\cdot\left(1-\dfrac{1}{100}\right)}\)
Chứng `M` có giá trị là 1 số nguyên
Hép - mi - pờ - li
