Violympic toán 7
Các câu hỏi tương tự
Tìm x biết: \(\left(\frac{1}{1\cdot2\cdot3}+\frac{1}{2\cdot3\cdot4}+\frac{1}{3\cdot4\cdot5}+...+\frac{1}{8\cdot9\cdot10}\right)\cdot x=\frac{22}{45}\).
Có công thức cho mình thì càng tốt!
Tính: B= \(\frac{1}{1\cdot2}+\frac{1}{2\cdot3}+\frac{1}{3\cdot4}+...+\frac{1}{99\cdot100}\)
Giúp mk vs trên violympic toàn bài chưa học thui
Tính \(\frac{A}{B}\) biết :
a) \(A=\frac{1}{1\cdot2}+\frac{1}{3\cdot4}+\frac{1}{5\cdot6}+...+\frac{1}{19\cdot20}\)
b) \(B=\frac{1}{11}+\frac{1}{12}+\frac{1}{13}+...+\frac{1}{19}+\frac{1}{20}\)
\(a.A=[\frac{1,5+1-0,75}{2,5+\frac{5}{3}-1,25}+\frac{0,375-0,3+\frac{3}{11}+\frac{3}{12}}{-0,625+0,5-\frac{5}{11}-\frac{5}{12}}]+\frac{1890}{2005}+115\)
b.B=\(\left[\frac{1\frac{11}{31}\cdot4\frac{3}{7}-\left(15-6\cdot\frac{1}{3}\cdot\frac{2}{19}\right)}{4\frac{5}{6}+\frac{1}{6}\left(42-5\frac{1}{3}\right)}\cdot\left(-1\frac{19}{93}\right)\right]\cdot\frac{31}{50}\)
Tính giá trị biểu thức
\(A=\left|x-\frac{1}{1\cdot2}\right|+\left|x-\frac{1}{2\cdot3}\right|+\left|x-\frac{1}{3\cdot4}\right|+...+\left|x-\frac{1}{100\cdot101}\right|+100x\)
Với \(x< 0\)
Cho \(A=\frac{1}{1\cdot2}+\frac{1}{3\cdot4}+\frac{1}{5\cdot6}+...+\frac{1}{99\cdot100}\)
Chứng minh rằng:
a) \(A=\frac{1}{51}+\frac{1}{52}+\frac{1}{53}+...+\frac{1}{100}\)
b) \(\frac{7}{12}< A< \frac{5}{6}\)
Bài 31 : Tính :
a) left(2^{-1}+3^{-1}right):left(2^{-1}-3^{-1}right)+left(2^{-1}.2^0right):2^3
b) left(-frac{1}{3}right)^{-1}-left(-frac{6}{7}right)^0+left(frac{1}{2}right)^2:2
c) text{[}left(0,1right)^2text{]}^0+text{[}left(frac{1}{7}right)^1text{]}^2.frac{1}{49}.text{[}left(2^3right)^3:2^5text{]}
Mong các cao nhân giúp ak , đang cần gấp
Đọc tiếp
Bài 31 : Tính :
a) \(\left(2^{-1}+3^{-1}\right):\left(2^{-1}-3^{-1}\right)+\left(2^{-1}.2^0\right):2^3\)
b) \(\left(-\frac{1}{3}\right)^{-1}-\left(-\frac{6}{7}\right)^0+\left(\frac{1}{2}\right)^2:2\)
c) \(\text{[}\left(0,1\right)^2\text{]}^0+\text{[}\left(\frac{1}{7}\right)^1\text{]}^2.\frac{1}{49}.\text{[}\left(2^3\right)^3:2^5\text{]}\)
Mong các cao nhân giúp ak , đang cần gấp
Bài 1: Tính
frac{3}{8}.19frac{1}{3}-frac{3}{8}.33frac{1}{3}
1frac{4}{23}+frac{5}{21}-frac{4}{23}+0,5+frac{16}{21}
frac{21}{47}+frac{9}{45}+frac{26}{47}+frac{4}{5}
frac{15}{12}+frac{5}{13}-frac{3}{12}-frac{18}{13}
frac{11}{24}-frac{5}{41}+frac{13}{24}+0,5-frac{36}{41}
left(-frac{3}{4}+frac{2}{3}right):frac{5}{11}+left(-frac{1}{4}+frac{1}{3}right):frac{5}{11}
left(-3right)^2.left(frac{3}{4}-0,25right)-left(3frac{1}{2}-1frac{1}{2}right)
Đọc tiếp
Bài 1: Tính
\(\frac{3}{8}.19\frac{1}{3}-\frac{3}{8}.33\frac{1}{3}\)
\(1\frac{4}{23}+\frac{5}{21}-\frac{4}{23}+0,5+\frac{16}{21}\)
\(\frac{21}{47}+\frac{9}{45}+\frac{26}{47}+\frac{4}{5}\)
\(\frac{15}{12}+\frac{5}{13}-\frac{3}{12}-\frac{18}{13}\)
\(\frac{11}{24}-\frac{5}{41}+\frac{13}{24}+0,5-\frac{36}{41}\)
\(\left(-\frac{3}{4}+\frac{2}{3}\right):\frac{5}{11}+\left(-\frac{1}{4}+\frac{1}{3}\right):\frac{5}{11}\)
\(\left(-3\right)^2.\left(\frac{3}{4}-0,25\right)-\left(3\frac{1}{2}-1\frac{1}{2}\right)\)
Tìm n∈Z biết :
a,27n/3n
b,frac{25}{5^n}5
c,frac{81}{left(-3right)^n}-243
d,frac{1}{2}cdot2^n+4cdot2^n9cdot2^5
e,(frac{1}{3})nfrac{1}{81}
f,left(frac{-3}{4}right)^nfrac{81}{256}
g,frac{-512}{343}left(frac{-8}{7}right)^n
h,5-1*25n125
k,3-1*3n+6*3n-17*36
Đọc tiếp
Tìm n∈Z biết :
a,27n/3n
b,\(\frac{25}{5^n}\)=5
c,\(\frac{81}{\left(-3\right)^n}=-243\)
d,\(\frac{1}{2}\cdot2^n+4\cdot2^n=9\cdot2^5\)
e,(\(\frac{1}{3}\))n=\(\frac{1}{81}\)
f,\(\left(\frac{-3}{4}\right)^n=\frac{81}{256}\)
g,\(\frac{-512}{343}=\left(\frac{-8}{7}\right)^n\)
h,5-1*25n=125
k,3-1*3n+6*3n-1=7*36