\(1001\left(\frac{2}{12012}+\frac{74}{555555}-\frac{2}{13.7.11.5}\right)\)
tính hợp lý
Những câu hỏi liên quan
Thực hiện phép tính hợp lý nhấta,A 1001.( frac{2}{12012}+frac{74}{555555} - frac{2}{13.7.11.5} )b,B -1frac{1}{6} .frac{1-frac{3}{5}+frac{3}{11}-frac{3}{11}}{frac{1}{3}-frac{1}{5}+frac{1}{11}-frac{1}{13}} :frac{4-frac{4}{17}+frac{4}{19}-frac{4}{2013}}{5-frac{5}{17}+frac{5}{19}-frac{5}{2013}}
Đọc tiếp
Thực hiện phép tính hợp lý nhất
a,A =1001.( \(\frac{2}{12012}\)+\(\frac{74}{555555}\) - \(\frac{2}{13.7.11.5}\) )
b,B= \(-1\frac{1}{6}\) .\(\frac{1-\frac{3}{5}+\frac{3}{11}-\frac{3}{11}}{\frac{1}{3}-\frac{1}{5}+\frac{1}{11}-\frac{1}{13}}\) :\(\frac{4-\frac{4}{17}+\frac{4}{19}-\frac{4}{2013}}{5-\frac{5}{17}+\frac{5}{19}-\frac{5}{2013}}\)
Tính nhanh:\(\frac{\left(1+2\right)\times3}{\left(2+3\right)\times4}+\frac{\left(2+3\right)\times4}{\left(3+4\right)\times5}+...+\frac{\left(999+1000\right)\times1001}{\left(1000+1001\right)\times1002}+\frac{\left(1000+1001\right)\times1002}{\left(1001+1002\right)\times1003}\)
Tính hợp lý
\(\left(\frac{-1}{2}\right)-\left(\frac{-3}{5}\right)+\left(\frac{-1}{9}\right)+\frac{1}{127}-\left(+\frac{7}{18}\right)+\frac{4}{35}-\left(\frac{-2}{7}\right)\)
\(=\left(-\frac{1}{2}-\frac{1}{9}-\frac{7}{18}\right)+\left(\frac{3}{5}+\frac{2}{7}+\frac{4}{35}\right)+\frac{1}{127}\)
\(=\left(-\frac{9}{18}-\frac{2}{18}-\frac{7}{18}\right)+\left(\frac{21}{35}+\frac{10}{35}+\frac{4}{35}\right)+\frac{1}{127}\)
\(=\left(-\frac{18}{18}\right)+\frac{35}{35}+\frac{1}{127}\)
\(=-1+1+\frac{1}{127}\)
\(=\frac{1}{127}\)
TÍNH HỢP LÝ
B=\(\left(\frac{2}{2.3}-1\right)\left(\frac{2}{3.4}-1\right)\left(\frac{2}{4.5}-1\right)...\left(\frac{2}{2008.2009}-1\right)\)
\(B=\left(\frac{2}{2.3}-1\right)\left(\frac{2}{3.4}-1\right)...\left(\frac{2}{2008.2009}-1\right)\)
\(B=\left(\frac{2}{2.3}-\frac{6}{2.3}\right)\left(\frac{2}{3.4}-\frac{12}{3.4}\right)...\left(\frac{2}{2008.2009}-\frac{2008.2009}{2008.2009}\right)\)
\(B=\left(-\frac{4}{2.3}\right)\left(-\frac{10}{3.4}\right)...\left(\frac{2-2008.2009}{2008.2009}\right)\)
\(B=\left(-\frac{1.4}{2.3}\right)\left(-\frac{2.5}{3.4}\right)...\left(-\frac{2007.2010}{2008.2009}\right)\)
Biểu thức B có (2008 - 2) : 1 + 1 = 2007 (thừa số)
Vì cả 2007 thừa số của biểu thức B đều mang dấu (-)
Nên biểu thức B mang dấu (-)
\(B=-\frac{1.2....2007}{2.3...2008}.\frac{4.5...2010}{3.4...2009}\)
\(B=-\frac{1}{2008}.\frac{2010}{3}\)
\(B=-\frac{1.2010}{2008.3}=-\frac{1.1005}{1004.3}=-\frac{1.335}{1004.1}\)
\(B=-\frac{335}{1004}\)
Vậy\(B=-\frac{335}{1004}\)
Đúng 0
Bình luận (0)
1.Tim so nguyen to lon nhat co 3 chu so sao cho so do chia het cho a-b; c-d; e-f; a/b=125/35; c/d=144/30;e/f=56/24
2. C=1001. (2/12012+74/555555+2/13.7.11.5)
D=(1.2+2.3+3.4+...+2012.2013)-(2.2+3.3+4.4+...+2013.2013)
3.Tìm số tự nhiên có 6 cs sao cho: abcdef=3.abc.def
4. Cho doan AB=7cm. Tren tia AB lay I sao cho BK=2cm
a. chung minh rang: I nam giua A va K
b. Tinh IK
Tính hợp lý:
\(\left(-\frac{1}{2}\right)+\left(-\frac{3}{5}\right)+\left(-\frac{1}{9}\right)+\frac{1}{127}-\frac{7}{18}+\frac{4}{35}-\left(-\frac{2}{7}\right)\)
Thực hiện phep tính một các hợp lý:
\(\left(\frac{2}{3}+\frac{2}{5}-\frac{2}{9}\right):\left(\frac{4}{3}+\frac{4}{5}-\frac{4}{9}\right)-\left(3-\frac{3}{11}-\frac{3}{17}\right):\left(5-\frac{5}{11}-\frac{5}{17}\right)\)
\(\frac{\frac{2}{3}+\frac{2}{5}-\frac{2}{9}}{\frac{4}{3}+\frac{4}{5}-\frac{4}{9}}\) _ \(\frac{3-\frac{3}{11}-\frac{3}{17}}{5-\frac{5}{11}-\frac{5}{17}}\)
=\(\frac{2\left(\frac{1}{3}+\frac{1}{5}-\frac{1}{9}\right)}{4\left(\frac{1}{3}+\frac{1}{5}-\frac{1}{9}\right)}\)_ \(\frac{3\left(1-\frac{1}{11}-\frac{1}{17}\right)}{5\left(1-\frac{1}{11}-\frac{1}{17}\right)}\)= \(\frac{2}{4}-\frac{3}{5}\)= \(\frac{-1}{10}\)
Đúng 0
Bình luận (0)
Tính hợp lý
\(\frac{3}{5}+\frac{3}{11}-\left(\frac{-3}{7}\right)+\left(\frac{2}{97}\right)-\frac{1}{35}-\frac{3}{4}+\left(\frac{-23}{44}\right)\)
\(\frac{3}{5}+\frac{3}{11}-\left(\frac{-3}{7}\right)+\frac{2}{97}-\frac{1}{35}-\frac{3}{4}+\left(\frac{-23}{44}\right)\)
\(=\frac{3}{5}+\frac{3}{11}+\frac{3}{7}+\frac{2}{97}-\frac{1}{35}-\frac{3}{4}-\frac{23}{44}\)
\(=\left(\frac{3}{5}+\frac{3}{7}-\frac{1}{35}\right)+\left(\frac{3}{11}-\frac{3}{4}-\frac{23}{44}\right)+\frac{2}{97}\)
\(=\left(\frac{21}{35}+\frac{15}{35}-\frac{1}{35}\right)+\left(\frac{12}{44}-\frac{33}{44}-\frac{23}{44}\right)+\frac{2}{97}\)
\(=\frac{35}{35}+\left(\frac{-44}{44}\right)+\frac{2}{97}=1+\left(-1\right)+\frac{2}{97}=\frac{2}{97}\)
\(=\left(\frac{3}{5}+\frac{3}{7}-\frac{1}{35}\right)+\left(\frac{3}{11}-\frac{3}{4}-\frac{23}{44}\right)+\frac{2}{97}\)
\(=\left(\frac{21}{35}+\frac{15}{35}-\frac{1}{35}\right)+\left(\frac{12}{44}-\frac{33}{44}-\frac{23}{44}\right)+\frac{2}{97}\)
\(=-1+1+\frac{2}{97}\)
\(=\frac{2}{97}\)
=[3/5+(-3/7)-1/35]+[3/11-3/4-(-23/44)]+2/97
=[21/35+(-15/35)-1/35]+[12/44-33/44-(-23/44)+2/97
=(-1)+1+2/97
=0+2/97
=2/97
tính hợp lý :
tính hợp lý:\(\left(-1-\frac{1}{12}\right).\left(-1-\frac{1}{13}\right).\left(-1-\frac{1}{14}\right)......\left(-1-\frac{1}{2017}\right)\)
\(\left(-1-\frac{1}{12}\right).\left(-1-\frac{1}{13}\right).\left(-1-\frac{1}{14}\right)...\left(-1-\frac{1}{2017}\right)\)
\(=\frac{-13}{12}.\frac{-14}{13}.\frac{-15}{14}...\frac{-2018}{2017}\)
\(=\frac{-13}{12}.\frac{14}{-13}.\frac{-15}{14}...\frac{2018}{-2017}\)
\(=\frac{\left(-13\right).14.\left(-15\right)...2018}{12.\left(-13\right).14...2017}=\frac{2018}{12}=\frac{1009}{6}\)
Đúng 0
Bình luận (0)