\(=-\left[\dfrac{-17}{21}+\dfrac{-19}{51}-\dfrac{4}{21}\right]+\dfrac{32}{51}\)
\(=1+\dfrac{19}{51}+\dfrac{32}{51}=1+1=2\)
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Chương III : Phân số
Các câu hỏi tương tự
Bài 1 : Tìm các số nguyên x , biết :
a) dfrac{2}{3}left(dfrac{1}{2}+dfrac{3}{4}-dfrac{1}{3}right)ledfrac{x}{18}ledfrac{7}{13}left(dfrac{1}{2}-dfrac{1}{6}right)
b) left(dfrac{31}{20}-dfrac{26}{45}right).-dfrac{36}{35} x left(dfrac{51}{56}+dfrac{8}{21}+dfrac{1}{3}right).dfrac{8}{13}
Bài 2 :
C dfrac{-1}{3}.dfrac{141}{17}-dfrac{39}{9}.dfrac{-1}{7}
Đọc tiếp
Bài 1 : Tìm các số nguyên x , biết :
a) \(\dfrac{2}{3}\left(\dfrac{1}{2}+\dfrac{3}{4}-\dfrac{1}{3}\right)\le\dfrac{x}{18}\le\dfrac{7}{13}\left(\dfrac{1}{2}-\dfrac{1}{6}\right)\)
b) \(\left(\dfrac{31}{20}-\dfrac{26}{45}\right).-\dfrac{36}{35}< x< \left(\dfrac{51}{56}+\dfrac{8}{21}+\dfrac{1}{3}\right).\dfrac{8}{13}\)
Bài 2 :
C = \(\dfrac{-1}{3}.\dfrac{141}{17}-\dfrac{39}{9}.\dfrac{-1}{7}\)
Tính nhanh tổng sau: \(M=\dfrac{2}{3}+\dfrac{9}{10}-\dfrac{11}{15}+\dfrac{13}{21}-\dfrac{15}{28}+\dfrac{17}{36}-\dfrac{19}{45}+\dfrac{21}{55}-\dfrac{23}{66}\)
Trình bày ra dùm mình nha!!
Xem chi tiết
1) dfrac{5}{13} +dfrac{-5}{17} + dfrac{-20}{41} + dfrac{8}{13} +dfrac{-21}{41}2) dfrac{1}{5} + dfrac{-2}{9} + dfrac{-7}{9} + dfrac{4}{5} +dfrac{16}{17}3) dfrac{2}{3.5} + dfrac{2}{5.7} +dfrac{2}{7.9} +....................+ dfrac{2}{99.101}
Đọc tiếp
1) \(\dfrac{5}{13}\) +\(\dfrac{-5}{17}\) + \(\dfrac{-20}{41}\) + \(\dfrac{8}{13}\) +\(\dfrac{-21}{41}\)
2) \(\dfrac{1}{5}\) + \(\dfrac{-2}{9}\) + \(\dfrac{-7}{9}\) + \(\dfrac{4}{5}\) +\(\dfrac{16}{17}\)
3) \(\dfrac{2}{3.5}\) + \(\dfrac{2}{5.7}\) +\(\dfrac{2}{7.9}\) +....................+ \(\dfrac{2}{99.101}\)
1:Tính
a) left(dfrac{1}{7}.x-dfrac{2}{7}right).left(dfrac{-1}{5}.x-dfrac{2}{5}right)0
b) dfrac{1}{6}.x+dfrac{1}{10}.x-dfrac{4}{5}.x+10
2:So sánh:
a) Aleft(dfrac{-46}{51}.0,32.dfrac{17}{20}right):dfrac{64}{75}
Bdfrac{-10}{11}.dfrac{8}{9}+dfrac{7}{8}.dfrac{10}{11}
b) Adfrac{-1}{3}+dfrac{0,2-0,375+dfrac{5}{11}}{-0,3+dfrac{9}{16}-dfrac{15}{22}}
Bdfrac{-43}{51}.dfrac{19}{80}
Đọc tiếp
1:Tính
a) \(\left(\dfrac{1}{7}.x-\dfrac{2}{7}\right).\left(\dfrac{-1}{5}.x-\dfrac{2}{5}\right)=0\)
b) \(\dfrac{1}{6}.x+\dfrac{1}{10}.x-\dfrac{4}{5}.x+1=0\)
2:So sánh:
a) A=\(\left(\dfrac{-46}{51}.0,32.\dfrac{17}{20}\right):\dfrac{64}{75}\)
B=\(\dfrac{-10}{11}.\dfrac{8}{9}+\dfrac{7}{8}.\dfrac{10}{11}\)
b) A=\(\dfrac{-1}{3}+\dfrac{0,2-0,375+\dfrac{5}{11}}{-0,3+\dfrac{9}{16}-\dfrac{15}{22}}\)
B=\(\dfrac{-43}{51}.\dfrac{19}{80}\)
Tính hợp lý: M=\(\dfrac{2}{3}+\dfrac{9}{10}-\dfrac{11}{15}_{ }+\dfrac{13}{21}-\dfrac{15}{28}+\dfrac{17}{36}-\dfrac{19}{45}+\dfrac{21}{55}-\dfrac{23}{66}\)
Giúp em nha!!!j) dfrac{-3}{4} + dfrac{2}{7} + dfrac{-1}{4} +dfrac{3}{5} +dfrac{5}{7}k) dfrac{-2}{17}+ dfrac{15}{23} + dfrac{-15}{17} + dfrac{4}{19} +dfrac{8}{23}
Đọc tiếp
j) \(\dfrac{-3}{4}\) + \(\dfrac{2}{7}\) + \(\dfrac{-1}{4}\) +\(\dfrac{3}{5}\) +\(\dfrac{5}{7}\)
k) \(\dfrac{-2}{17}\)+ \(\dfrac{15}{23}\) + \(\dfrac{-15}{17}\) + \(\dfrac{4}{19}\) +\(\dfrac{8}{23}\)
Thực hiện phép tính ( tính nhanh nếu có thể ) a, -5/21 + -2/21 + 8/24b, 4/11 . -2/7 + 4/11 . -4/7 + 4/11 . -1/7c, 10dfrac{5}{9} - ( 3dfrac{5}{7} + 4dfrac{5}{9} )d, 1/3 + 1dfrac{3}{4} - ( 1dfrac{3}{4} - 80% )e, 5dfrac{3}{5} + 7dfrac{21}{48} : 10/7 - 5dfrac{21}{48} : 10/7f, -5/7 . 2/11 - 5/11 . 9/7 + 2dfrac{5}{7}g, -3/13 . 6/8 + 7/13 . -3/8 + 1dfrac{3}{8}
Đọc tiếp
Thực hiện phép tính ( tính nhanh nếu có thể )
a, -5/21 + -2/21 + 8/24
b, 4/11 . -2/7 + 4/11 . -4/7 + 4/11 . -1/7
c, \(10\dfrac{5}{9}\) - ( \(3\dfrac{5}{7}\) + \(4\dfrac{5}{9}\) )
d, 1/3 + \(1\dfrac{3}{4}\) - ( \(1\dfrac{3}{4}\) - 80% )
e, \(5\dfrac{3}{5}\) + \(7\dfrac{21}{48}\) : 10/7 - \(5\dfrac{21}{48}\) : 10/7
f, -5/7 . 2/11 - 5/11 . 9/7 + \(2\dfrac{5}{7}\)
g, -3/13 . 6/8 + 7/13 . -3/8 + \(1\dfrac{3}{8}\)
Tính E = \(\dfrac{\dfrac{1}{51}+\dfrac{1}{52}+\dfrac{1}{53}+.....+\dfrac{1}{100}}{\dfrac{1}{1.2}+\dfrac{1}{3.4}+\dfrac{1}{5.6}+....+\dfrac{1}{99.100}}\)
\(-31\dfrac{4}{9} - 5 . ( \dfrac{2}{3} . x + 1\dfrac{1}{2})=-21\dfrac{4}{9}\)