cho M = \(\frac{4}{31\cdot7}\)+\(\frac{6}{7\cdot41}\)+\(\frac{9}{10\cdot41}\)+\(\frac{7}{10\cdot57}\)và N = \(\frac{7}{19\cdot31}\)+\(\frac{5}{19\cdot43}\)+\(\frac{3}{23\cdot43}\)+\(\frac{11}{23\cdot57}\). Tính M/N
Tính tỉ số \(\frac{A}{B}\) biết : A = \(\frac{4}{7\cdot31}\)+\(\frac{6}{7\cdot41}\)+\(\frac{9}{10\cdot41}\)+\(\frac{7}{10\cdot57}\)và B = \(\frac{7}{19\cdot31}\)+ \(\frac{5}{19\cdot43}\) + \(\frac{3}{23\cdot43}\)+ \(\frac{11}{23\cdot57}\)
Bài 1 :Tính tỉ số A/B biết
a) \(A=\frac{4}{7\cdot31}+\frac{6}{7\cdot41}+\frac{9}{10\cdot41}+\frac{7}{10\cdot57}\)
\(B=\frac{7}{19\cdot31}+\frac{5}{19\cdot43}+\frac{3}{23\cdot43}+\frac{11}{23\cdot57}\)
b)\(A=\frac{40}{31\cdot39}+\frac{35}{39\cdot46}+\frac{30}{46\cdot52}+\frac{25}{52\cdot57}\)
\(B=\frac{91}{19\cdot31}+\frac{65}{19\cdot43}+\frac{39}{989}+\frac{143}{1311}\)
Bài 2 : Tính Avà B biết :
a) \(A=\frac{2006}{1\cdot2}+\frac{2006}{2\cdot3}+...+\frac{2006}{2006\cdot2007}\)
\(B=\frac{1}{1\cdot2\cdot3}+\frac{1}{2\cdot3\cdot4}+...+\frac{1}{2004\cdot2005\cdot2006}\)
Tính :
\(B=\left(\frac{7}{19\cdot31}+\frac{5}{19\cdot43}+\frac{3}{23\cdot43}+\frac{11}{23\cdot57}\right)\div\left(\frac{1}{31}-\frac{1}{57}\right)\)
\(B=\frac{4}{7\cdot31}+\frac{6}{7\cdot41}+\frac{9}{10\cdot41}+\frac{7}{10\cdot57}\)
Tính \(\frac{M}{N}\)biết :
M = \(\frac{2}{7\cdot19}+\frac{6}{7\cdot27}+\frac{1}{4\cdot9}+\frac{7}{12\cdot43}+\frac{8}{17\cdot43}\)
N = \(\frac{9}{7\cdot19}+\frac{5}{7\cdot33}+\frac{7}{10\cdot33}+\frac{11}{10\cdot31}\)
Tính
\(1\frac{5}{7}-\frac{5}{7}.\frac{2}{11}-\frac{5}{7}.\frac{9}{11}\)
\(\frac{3}{11}.\frac{7}{19}.\frac{17}{11}.\frac{3}{9}-\frac{3}{19}.\frac{15}{11}\)
\(\frac{5}{11}.\frac{18}{29}-\frac{5}{11}.\frac{8}{29}+\frac{5}{11}.\frac{19}{26}\)
\(\frac{17}{23}.\frac{8}{16}.\frac{27}{17}.80.\frac{3}{4}\)
\(\left(\frac{13}{23}+\frac{1313}{2323}-\frac{131313}{232323}\right).\left(\frac{1}{3}+\frac{1}{4}-\frac{7}{12}\right)\)
Tính nhanh:
a) \(2.\frac{3}{7}+\left(\frac{2}{9}-1\frac{3}{7}\right)-\frac{5}{3}:\frac{1}{9}\)
b) \(\frac{-11}{23}.\frac{6}{7}+\frac{8}{7}.\frac{-11}{23}-\frac{1}{23}\)
c )\(\left(\frac{377}{-231}-\frac{123}{89}+\frac{34}{791}\right).\left(\frac{1}{6}-\frac{1}{8}-\frac{1}{24}\right)\)
d) \(19\frac{5}{8}:\frac{7}{12}-15\frac{1}{4}:\frac{7}{12}\)
e) \(\frac{2}{5}.\frac{1}{3}-\frac{2}{15}:\frac{1}{5}+\frac{3}{5}.\frac{1}{3}\)
B1: Thực hiện phép tính :
a, \(11\frac{3}{4}-(6\frac{5}{6}-4\frac{1}{2})+1\frac{2}{3}\)
b, \(2\frac{17}{20}-1\frac{11}{5}+6\frac{9}{20}:3\)
c, \(4\frac{3}{7}:\left(\frac{7}{5}.4\frac{3}{7}\right)\)
d, \(\left(3\frac{2}{9}.\frac{15}{23}.1\frac{7}{29}\right):\frac{5}{23}\)
B2: Thực hiện phép tính:
\(a,11\frac{3}{4}-(6\frac{5}{6}4\frac{1}{2}+1\frac{2}{3})\\ b,\left(5\frac{7}{8}-2\frac{1}{4}-0,5\right):\frac{23}{26}\)
\(c,\left(17\frac{13}{15}-3\frac{3}{7}\right)-\left(2\frac{12}{15}-4\right)\\ d,2\frac{2}{3}.\frac{-4}{5}.0,375-\left(-10\right).\frac{-15}{24}\)