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Các câu hỏi tương tự
Cho A = \(\dfrac{\left(3\dfrac{2}{15}+\dfrac{1}{5}\right):2\dfrac{1}{2}}{\left(5\dfrac{3}{7}-2\dfrac{1}{4}\right):4\dfrac{43}{56}}\) ; B = \(\dfrac{1,2:\left(1\dfrac{1}{5}.1\dfrac{1}{4}\right)}{0,32+\dfrac{2}{25}}\)
Chứng minh rằng A= B
a, \(\dfrac{1}{3}.\dfrac{4}{5}+\dfrac{1}{3}.\dfrac{6}{5}-\dfrac{4}{3}\)
b, \(\dfrac{4}{19}-\dfrac{-3}{7}+\dfrac{-3}{7}.\dfrac{15}{19}+\dfrac{5}{7}\)
c, \(\dfrac{5}{9}.\dfrac{7}{13}+\dfrac{5}{9}.\dfrac{9}{13}-\dfrac{5}{9}.\dfrac{3}{13}\)
Chứng minh:
\(\dfrac{1}{3^2}+\dfrac{1}{4^2}+\dfrac{1}{5^2}+\dfrac{1}{6^2}+...+\dfrac{1}{100^2}và< \dfrac{1}{2}\)
1. Chứng minh:
\(\dfrac{1}{3}-\dfrac{2}{3^2}+\dfrac{3}{3^3}-\dfrac{4}{3^4}+...+\dfrac{99}{3^{99}}-\dfrac{100}{3^{100}}< \dfrac{3}{16}\)
2. Cho:
\(M=\dfrac{1}{15}+\dfrac{1}{105}+\dfrac{1}{315}+...+\dfrac{1}{1977}\). So sánh M với 12.
Chứng minh rằng :
a) \(1-\dfrac{1}{2}+\dfrac{1}{3}-\dfrac{1}{4}+...+\dfrac{1}{199}-\dfrac{1}{200}=\dfrac{1}{101}\)+ \(\dfrac{1}{102}+...+\dfrac{1}{200}\)
Tính
a, 4timesleft(-dfrac{1}{2}right)^3-2timesleft(-dfrac{1}{2}right)^2+3timesleft(-dfrac{1}{2}right)+1
b, dfrac{4^6times9^5+6^9times120}{-8^4times3^{12}+6^{11}}
c, dfrac{155-dfrac{10}{7}-dfrac{5}{11}+dfrac{5}{23}}{403-dfrac{26}{7}-dfrac{13}{11}+dfrac{12}{23}}+dfrac{dfrac{3}{5}+dfrac{3}{13}-0,9}{dfrac{7}{91}+0,2-dfrac{3}{10}}
d,dfrac{30times4^7times3^{29}-5times14^5times2^{12}}{54times6^{14}times9^7-12times8^5times7^5}
Đọc tiếp
Tính
a, 4\(\times\left(-\dfrac{1}{2}\right)^3-2\times\left(-\dfrac{1}{2}\right)^2+3\times\left(-\dfrac{1}{2}\right)+1\)
b, \(\dfrac{4^6\times9^5+6^9\times120}{-8^4\times3^{12}+6^{11}}\)
c, \(\dfrac{155-\dfrac{10}{7}-\dfrac{5}{11}+\dfrac{5}{23}}{403-\dfrac{26}{7}-\dfrac{13}{11}+\dfrac{12}{23}}+\dfrac{\dfrac{3}{5}+\dfrac{3}{13}-0,9}{\dfrac{7}{91}+0,2-\dfrac{3}{10}}\)
d,\(\dfrac{30\times4^7\times3^{29}-5\times14^5\times2^{12}}{54\times6^{14}\times9^7-12\times8^5\times7^5}\)
Tính :
a) \(1\dfrac{13}{15}.\left(0,5\right)^2.3+\left(\dfrac{8}{15}-1\dfrac{19}{60}\right):1\dfrac{23}{24}\)
b) \(\dfrac{\left(\dfrac{11^2}{200}+0,415\right):0,01}{\dfrac{1}{12}-37,25+3\dfrac{1}{6}}\)
Chung minh
\(A=\dfrac{1}{10}+\dfrac{1}{12}+\dfrac{1}{14}+.....+\dfrac{1}{20}\)\(< \dfrac{1}{2}\)
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}{3.7}+...+dfrac{5}{99.101}
C dfrac{1}{2.3}+dfrac{1}{3.4}+...+dfrac{1}{99.100} D dfrac{5}{1.4}+dfrac{5}{4.7}+...+dfrac{5}{100.103} E dfrac{1}{15}+dfrac{1}{35}+...+dfrac{1}{2499}
Đọc tiếp
tính tổng: A= \(\dfrac{2}{1.3}+\dfrac{2}{3.5}+\dfrac{2}{5.7}+...+\dfrac{2}{99.101}\) B= \(\dfrac{5}{1.3}+\dfrac{5}{3.5}+\dfrac{5}{3.7}+...+\dfrac{5}{99.101}\)
C= \(\dfrac{1}{2.3}+\dfrac{1}{3.4}+...+\dfrac{1}{99.100}\) D= \(\dfrac{5}{1.4}+\dfrac{5}{4.7}+...+\dfrac{5}{100.103}\) E= \(\dfrac{1}{15}+\dfrac{1}{35}+...+\dfrac{1}{2499}\)