\(=\dfrac{1}{4}+\dfrac{1}{5}-\dfrac{1}{5}-\dfrac{1}{6}+\dfrac{1}{6}+\dfrac{1}{7}-...+\dfrac{1}{98}+\dfrac{1}{99}-\dfrac{1}{99}-\dfrac{1}{100}\)
=1/4-1/100
=25/100-1/100
=24/100=6/25
A=\(\dfrac{38}{50}\)+\(\dfrac{9}{20}\)-\(\dfrac{11}{30}\)+\(\dfrac{13}{42}\)-\(\dfrac{15}{56}\)+\(\dfrac{17}{72}\)-...+\(\dfrac{197}{9702}\)-\(\dfrac{199}{9900}\)
tính hợp lí:
\(\dfrac{8}{9}-\dfrac{1}{72}-\dfrac{1}{56}-\dfrac{1}{42}-\dfrac{1}{30}-\dfrac{1}{20}-\dfrac{1}{12}-\dfrac{1}{6}-\dfrac{1}{2}\)
Thực hiện phép tính (hợp lí nếu có thể):
a) \(13\dfrac{2}{7}\) : (\(\dfrac{-8}{9}\)) + \(2\dfrac{5}{7}\) : (\(\dfrac{-8}{9}\))
b) (\(\dfrac{-6}{11}\)) . \(\dfrac{7}{10}\) . (\(\dfrac{11}{-6}\)) . (-20)
c) (\(-1\dfrac{1}{2}\)) : \(\dfrac{3}{4}\) . (\(-4\dfrac{1}{2}\))
Tính (hợp lí nếu có thể)
\(\dfrac{1}{3}\) - \(\dfrac{3}{5}\) + \(\dfrac{5}{7}\) - \(\dfrac{7}{9}\) + \(\dfrac{9}{11}\) - \(\dfrac{11}{13}\) + \(\dfrac{13}{15}\) + \(\dfrac{11}{13}\) - \(\dfrac{9}{11}\) + \(\dfrac{7}{9}\) - \(\dfrac{5}{7}\) + \(\dfrac{3}{5}\) - \(\dfrac{1}{3}\)
\(\dfrac{-5}{9}.15\dfrac{11}{13}-\dfrac{-5}{9}.11\dfrac{11}{13}+\dfrac{5}{9}\)
Thực hiện phép tính (hợp lí nếu có thể):
a) (\(\dfrac{-6}{11}\)) . \(\dfrac{7}{10}\) . \(\dfrac{11}{-6}\) . (-20)
b) (\(-1\dfrac{1}{2}\)) : \(\dfrac{3}{4}\) . \(-4\dfrac{1}{2}\))
c) \(13\dfrac{2}{7}\) : (\(\dfrac{-8}{9}\)) + \(2\dfrac{5}{7}\) : (\(\dfrac{-8}{9}\))
\(\dfrac{-10}{13}\)+\(\dfrac{5}{7}\)-\(\dfrac{3}{13}\)+\(\dfrac{2}{17}\)-\(\dfrac{11}{20}\)
( làm chi tiết )
Giúp mình nha cảm ơn bạn nhiều lắm!
A= \(\dfrac{1}{50}-\dfrac{1}{6}-\dfrac{1}{12}-\dfrac{1}{20}-\dfrac{1}{30}-\dfrac{1}{42}\)
\(-\left(\dfrac{2}{11}+\dfrac{3}{13}\right)-\left(-\dfrac{3}{13}+\dfrac{9}{11}\right)\)
bài 7 tìm những giá trị nhuyên dương X thỏa mãn
3) \(\dfrac{-5}{11}\)<\(\dfrac{9}{x}\)<\(\dfrac{-5}{12}\)
4) \(\dfrac{-11}{13}\)<\(\dfrac{9}{x}\)<\(\dfrac{-11}{15}\)
5) \(\dfrac{-4}{5}\)<\(\dfrac{9}{x}\)<\(\dfrac{-4}{7}\)
nhanh cần gấp nhé
