\(P=\frac{\frac{2}{3}-\frac{1}{4}+\frac{5}{11}}{\frac{5}{12}+1-\frac{7}{11}}\)
a)\(\frac{1}{2}+\frac{1}{2^2}+\frac{1}{2^3}+...+\frac{1}{2^{20}}\)
b)\(\frac{\frac{2}{3}+\frac{5}{7}+\frac{4}{21}}{\frac{5}{6}+\frac{11}{7}-\frac{7}{21}}\)
c)\(\left(\frac{\frac{3}{5}+\frac{3}{11}-\frac{3}{17}}{1+\frac{5}{11}-\frac{5}{17}}+\frac{\frac{4}{7}-\frac{8}{23}-\frac{12}{139}}{\frac{5}{7}-\frac{10}{23}-\frac{7}{21}}\right):3\frac{1}{5}\)
GIÚP MÌNH VỚI Ạ
b) \(\frac{\frac{2}{3}+\frac{5}{7}+\frac{4}{21}}{\frac{5}{6}+\frac{11}{7}-\frac{7}{21}}\)
\(=\frac{\frac{29}{21}+\frac{4}{21}}{\frac{101}{42}-\frac{7}{21}}\)
\(=\frac{\frac{11}{7}}{\frac{29}{14}}\)
\(=\frac{22}{29}.\)
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Rút gọn
1.\(\frac{7}{19}.\frac{8}{11}+\frac{7}{19}.\frac{3}{11}+\frac{12}{19}\)
2.\(\frac{\frac{2}{5}+\frac{2}{7}-\frac{2}{9}-\frac{2}{11}}{\frac{4}{5}+\frac{4}{7}-\frac{4}{9}-\frac{4}{11}}\)
\(1\)) \(\frac{7}{19}.\frac{8}{11}+\frac{7}{19}.\frac{3}{11}+\frac{12}{19}\)
\(=\frac{7}{19}\left(\frac{8}{11}+\frac{3}{11}\right)+\frac{12}{19}\)
\(=\frac{7}{19}+\frac{12}{19}\)
\(=1\)
\(2\)) \(\frac{\frac{2}{5}+\frac{2}{7}-\frac{2}{9}-\frac{2}{11}}{\frac{4}{5}+\frac{4}{7}-\frac{4}{9}-\frac{4}{11}}\)
\(=\frac{\frac{2}{5}+\frac{2}{7}-\frac{2}{9}-\frac{2}{11}}{2\left(\frac{2}{5}+\frac{2}{7}-\frac{2}{9}-\frac{2}{11}\right)}\)
\(=\frac{1}{2}\)
1. \(\frac{7}{19}\times\frac{8}{11}+\frac{7}{19}\times\frac{3}{11}+\frac{12}{19}\)
\(=\frac{7}{19}\left(\frac{8}{11}+\frac{3}{11}\right)+\frac{12}{19}\)
\(=\frac{7}{19}\times1+\frac{12}{19}=\frac{19}{19}=1\)
2. \(\frac{\frac{2}{5}+\frac{2}{7}-\frac{2}{9}-\frac{2}{11}}{\frac{4}{5}+\frac{4}{7}-\frac{4}{9}-\frac{4}{11}}\)
\(=\frac{\frac{2}{5}+\frac{2}{7}-\frac{2}{9}-\frac{2}{11}}{2\left(\frac{2}{5}+\frac{2}{7}-\frac{2}{9}-\frac{2}{11}\right)}=\frac{1}{2}\)
Tính
\(1\frac{5}{7}-\frac{5}{7}.\frac{2}{11}-\frac{5}{7}.\frac{9}{11}\)
\(\frac{3}{11}.\frac{7}{19}.\frac{17}{11}.\frac{3}{9}-\frac{3}{19}.\frac{15}{11}\)
\(\frac{5}{11}.\frac{18}{29}-\frac{5}{11}.\frac{8}{29}+\frac{5}{11}.\frac{19}{26}\)
\(\frac{17}{23}.\frac{8}{16}.\frac{27}{17}.80.\frac{3}{4}\)
\(\left(\frac{13}{23}+\frac{1313}{2323}-\frac{131313}{232323}\right).\left(\frac{1}{3}+\frac{1}{4}-\frac{7}{12}\right)\)
P = \(\frac{\frac{2}{3}+\frac{1}{4}+\frac{5}{11}}{\frac{5}{12}+1-\frac{7}{11}}\)
tính nhanh:P=\(\frac{\frac{2}{3}-\frac{1}{4}+\frac{5}{11}}{\frac{5}{12}+1-\frac{7}{11}}\)
\(\frac{\left(\frac{2}{3}-\frac{1}{4}\right)+\frac{5}{11}}{\frac{5}{12}+\left(1-\frac{7}{11}\right)}=\frac{\frac{5}{12}+\frac{5}{11}}{\frac{5}{12}+\frac{5}{11}}=1\)
tính nhanh: P=\(\frac{\frac{2}{3}-\frac{1}{4}+\frac{5}{11}}{\frac{5}{12}+1-\frac{7}{11}}\)
\(P=\frac{\frac{2}{3}-\frac{1}{4}+\frac{5}{11}}{\frac{5}{12}+1-\frac{7}{11}}\)
\(\Rightarrow P=\frac{\frac{8}{12}-\frac{3}{12}+\frac{5}{11}}{\frac{5}{12}+\frac{11}{11}-\frac{7}{11}}\)
\(\Rightarrow P=\frac{\frac{5}{12}+\frac{5}{11}}{\frac{5}{12}+\frac{4}{11}}\)
Chúc bạn học tốt !!!
Tính nhanh: P=\(\frac{\frac{2}{3}-\frac{1}{4}+\frac{5}{11}}{\frac{5}{12}-1-\frac{7}{11}}\)
tính nhanh
\(5\frac{2}{7}.\frac{8}{11}+5\frac{2}{7}.\frac{5}{11}-5\frac{2}{7}.\frac{2}{11}\)
\(\left(\frac{67}{111}+\frac{2}{33}-\frac{15}{117}\right).\left(\frac{1}{3}-\frac{1}{4}-\frac{1}{12}\right)\)
1) \(5\frac{2}{7}\).\(\frac{8}{11}\)+\(5\frac{2}{7}.\frac{5}{11}+5\frac{2}{7}.\frac{-2}{11}\)
= \(5\frac{2}{7}\).[\(\frac{8}{11}+\frac{5}{11}+\frac{-2}{11}\)]
= \(5\frac{2}{7}\).1
=\(5\frac{2}{7}\)
2)
5 2/7.8/9+5 2/7.5/11-5 2/7.2/11
=5 2/7.(8/11+5/11+2/11)
=5 2/7.15/11
=240/77.
(67/111+2/33-15/117).(1/3-1/4-1/12)
=811/1221.1/12
=811/14652