So sánh các phân số sau theo cách thuận tiện nhất:

a.\(\frac{17}{19}\)và \(\frac{19}{17}\)

b.\(\frac{15}{7}\)và \(\frac{25}{12}\)

c.A=\(\frac{3^{10}+1}{3^9+1}\)và B= \(\frac{3^9+1}{3^8+1}\)

d.A=\(\frac{54.107-53}{53.107+54}\)và B=\(\frac{135.269-133}{134.269+135}\)

Tính:

a) \(A=\frac{(1+17)(1+\frac{17}{2})(1+\frac{17}{3})...(1+\frac{17}{19})}{(1+19)(1+\frac{19}{2})(1+\frac{19}{3})...(1+\frac{19}{17})}\)

b) \(B=\frac{1}{-2}.\frac{1}{3}+\frac{1}{-3}.\frac{1}{4}+...+\frac{1}{-5}.\frac{1}{10}\)

c) \(C=(1-\frac{1}{1.2})+(1-\frac{1}{2.3})+...+(1-\frac{1}{2015.2016})\)

d) \(D=\frac{\frac{9}{1}+\frac{8}{2}+\frac{7}{3}+...+\frac{1}{9}}{\frac{1}{2}+\frac{1}{3}+\frac{1}{3}+...+\frac{1}{10}}\)

Tính giá trị biểu thức

\(1.A=\frac{1}{5}+\frac{3}{17}-\frac{4}{3}+\left(\frac{4}{5}-\frac{3}{17}+\frac{1}{3}\right)-\frac{1}{7}+\left[\frac{-14}{30}\right]\)

\(2.B=\left(\frac{5}{8}-\frac{4}{12}+\frac{3}{2}\right)-\left(\frac{5}{8}+\frac{9}{13}\right)-\left[\frac{-3}{2}\right]+\frac{7}{-15}\)

\(3.C=\frac{5}{18}+\frac{8}{19}-\frac{7}{21}+\left(\frac{-10}{36}+\frac{11}{19}+\frac{1}{3}\right)-\frac{5}{8}\)

\(4.D=\frac{1}{9}-\left[\frac{-5}{23}\right]-\left(\frac{-5}{23}+\frac{1}{9}+\frac{25}{7}\right)+\frac{50}{14}-\frac{7}{30}\)

\(5.E=\frac{1}{13}+\left(\frac{-5}{18}-\frac{1}{13}+\frac{12}{17}\right)+\left(\frac{12}{17}+\frac{5}{18}+\frac{7}{5}\right)\)

\(6.F=\frac{15}{14}-\left(\frac{17}{23}-\frac{80}{87}+\frac{5}{4}\right)+\left(\frac{12}{17}-\frac{15}{14}+\frac{1}{4}\right)\)

\(7.G=\frac{1}{25}-\frac{4}{27}+\left(\frac{-23}{27}+\frac{-1}{25}-\frac{5}{43}\right)+\frac{5}{43}-\frac{4}{7}\)

\(8.H=\frac{4}{15}-\frac{23}{28}-\left(\frac{-23}{28}+\frac{-11}{15}-\frac{29}{27}\right)-\frac{2}{27}\)

\(9.K=\frac{1}{16}-\frac{5}{21}+\left(\frac{-1}{16}+\frac{-3}{5}-\frac{-5}{21}\right)+\frac{-2}{5}+\frac{3}{4}\)

\(10.L=\frac{7}{12}+\frac{15}{14}-\left(\frac{14}{22}+\frac{-1}{14}+\frac{5}{21}\right)-\frac{-5}{21}+\frac{3}{5}\)

\(\text{So sánh: A=\frac{1}{2\cdot3}+\frac{1}{4\cdot5}+\frac{1}{6\cdot7}+\frac{1}{8\cdot9}+\frac{1}{10\cdot11}+\frac{1}{12\cdot13}+\frac{1}{14\cdot15}+\frac{1}{16\cdot17}+\frac{1}{18\cdot19} và B=\frac{9}{19}}\)So sánh: A=1/2*3 + 1/4*5 + 1/6*7 + 1/8*9 + 1/10*11 + 1/12*13 + 1/14*15 + 1/16*17 + 1/18*19 và B=9/19

Giúp tớ với, tớ cần gấp !! Cảm ơn nhìu ạ !!

Bài 1.hãy sắp xếp hết số hữu tỉ sau theo thứ tự tăng dần

a,\(\frac{19}{33};\frac{6}{11}và\frac{13}{22}\)

b, \(\frac{-18}{12};\frac{-10}{7};\frac{-8}{5}\)

bài 2 so sánh các số hữu tỉ sau theo cách nhanh nhất

a,-4 và \(\frac{1}{13}\)

b,\(\frac{11}{12}và\frac{19}{18}\)

c, \(\frac{-17}{16}và\frac{-33}{34}\)

d, \(\frac{3}{8}và\frac{13}{40}\)

e, \(\frac{2001}{-2002}va\frac{4587}{4565}\)

Bài 1: tính nhanh

a)\(6\frac{4}{5}-\left(1\frac{2}{3}+3\frac{4}{5}\right)\)

b)\(\left(\frac{-4}{5}+\frac{4}{3}\right)+\left(\frac{-5}{4}+\frac{14}{5}\right)-\frac{7}{3}\)

c)\(\frac{8}{3}.\frac{2}{5}.\frac{3}{8}.10\frac{19}{92}\)

d)\(\frac{-5}{7}.\frac{2}{11}+\frac{-5}{7}.\frac{9}{14}+1\frac{5}{7}\)

e)\(\frac{12}{19}.\frac{7}{15}.\frac{-13}{17}.\frac{19}{12}.\frac{17}{13}\)