Các câu hỏi tương tự
Bài 1: Thực hiện phép tính 1 cách hợp lý : a) left(1+frac{1}{1.3}right).left(1+frac{1}{2.4}right).left(1+frac{1}{3.5}right)...left(1+frac{1}{2009.2011}right)b) frac{16}{9}-frac{1}{36}-frac{1}{28}-frac{1}{21}-frac{1}{15}-frac{1}{10}-frac{1}{6}-frac{1}{3}-1 c) frac{0,4-frac{2}{9}+frac{2}{11}-frac{2}{37}}{1,4-frac{7}{9}-frac{7}{11}-frac{7}{37}}-frac{frac{1}{3}-0,25+frac{1}{5}}{1frac{1}{6}-0,785+0,7}
Đọc tiếp
Bài 1: Thực hiện phép tính 1 cách hợp lý :
\(a\)) \(\left(1+\frac{1}{1.3}\right).\left(1+\frac{1}{2.4}\right).\left(1+\frac{1}{3.5}\right)...\left(1+\frac{1}{2009.2011}\right)\)
\(b\)) \(\frac{16}{9}-\frac{1}{36}-\frac{1}{28}-\frac{1}{21}-\frac{1}{15}-\frac{1}{10}-\frac{1}{6}-\frac{1}{3}-1\)
\(c\)) \(\frac{0,4-\frac{2}{9}+\frac{2}{11}-\frac{2}{37}}{1,4-\frac{7}{9}-\frac{7}{11}-\frac{7}{37}}-\frac{\frac{1}{3}-0,25+\frac{1}{5}}{1\frac{1}{6}-0,785+0,7}\)
1+\(\frac{1}{3}+\frac{1}{6}+\frac{1}{10}+\frac{1}{15}+\frac{1}{21}+\frac{1}{28}+\frac{1}{36}+\frac{1}{45}\)
1. Tính hợp lý
\(\frac{\frac{1}{9}-\frac{5}{6}-4}{\frac{7}{12}-\frac{1}{36}-10}\)
2. CMr:
\(\frac{1}{26}+\frac{1}{27}+\frac{1}{28}+...+\frac{1}{50}=1-\frac{1}{2}+\frac{1}{3}-\frac{1}{4}+...+\frac{1}{49}-\frac{1}{50}\)
\(\frac{1}{45}-\frac{1}{36}-\frac{1}{28}-\frac{1}{21}-\frac{1}{15}-\frac{1}{10}-\frac{1}{6}-\frac{1}{3}-1\)
Tính nhanh
\(A=1+\frac{1}{3}+\frac{1}{6}+\frac{1}{10}+\frac{1}{15}+\frac{1}{21}+\frac{1}{28}+\frac{1}{36}+\frac{1}{45}\)\(\frac{1}{45}\)
Nhanh tk !!
Tính nhanh nếu có thể:
a)
\(\frac{1}{3}+\frac{1}{15}+\frac{1}{35}+\frac{1}{63}+\frac{1}{99}+\frac{1}{143}+\frac{1}{195}\)
b)
\(1+\frac{1}{3}+\frac{1}{6}+\frac{1}{10}+\frac{1}{15}+\frac{1}{21}+\frac{1}{28}+\frac{1}{36}+\frac{1}{45}+\frac{1}{55}+\frac{1}{66}\)
\(\frac{1}{6}+\frac{1}{10}+\frac{1}{15}+\frac{1}{21}+\frac{1}{28}+\frac{1}{36}+\frac{1}{45}=m\text{ấ}y\)
\(E=\left(\frac{1}{3}-1\right)\left(\frac{1}{6}-1\right)\left(\frac{1}{10}-1\right)\left(\frac{1}{15}-1\right)\left(\frac{1}{21}-1\right)\left(\frac{1}{28}-1\right)\left(\frac{1}{36}-1\right)\)
Tính các tích sau:
a)\(A=\frac{3}{4}.\frac{8}{9}.\frac{15}{16}.....\frac{9999}{10000}\)
b)\(B=\left(1-\frac{1}{21}\right).\left(1-\frac{1}{28}\right).\left(1-\frac{1}{36}\right)......\left(1-\frac{1}{1326}\right)\)
c)\(C=\left(1+\frac{1}{1.3}\right).\left(1+\frac{1}{2.4}\right).\left(1+\frac{1}{3.5}\right)....\left(1+\frac{1}{99.101}\right)\)