\(\frac{15.8+15}{5.9}\)
4\(\frac{1}{2}\)-\(\frac{15}{10.9}-\frac{15}{9.8}-...-\frac{15}{3.2}-\frac{15}{2.1}\)
\(\frac{6}{2.5}+\frac{8}{5.9}+\frac{12}{9.15}\)
\(1-\frac{2}{2.1}-\frac{6}{2.5}-\frac{8}{5.9}-\frac{8}{9.13}\)
Tính :
a, \(\frac{15}{1.6}.\frac{15}{6.11}.\frac{15}{11.16}...\frac{15}{2011.2016}\)
b, \(\frac{4^5.9^4-2.6^9}{2^{10}.3^8+6^8.20}:\sqrt{\frac{25}{9}}\)
Quy đồng mẫu các phân số sau:
a) \(\frac{4.5+4.11}{8.7-4.3}\) và \(\frac{15.8-10.7}{5.6+20.3}\)
b) \(4\frac{15}{105};3\frac{128}{144};2\frac{63}{324}\)
2^27.9^8/6^15.8^15
giải giúp em với ạ.E đang cần gấp
\(\frac{2^{27}.9^8}{6^{15}.8^{15}}\)
\(=\frac{2^{27}.3^{16}}{2^{60}.3^{15}}\)
\(=\frac{3}{2^{33}}\)
Rút gọn
\(\frac{-15.8+10.7}{5.6+20.3}\)
Rút gọn :
\(\frac{15.8+15.4}{12.3}\)
Ai nhanh mk k cho
\(\frac{15.8+15.4}{12.3}=\frac{15.\left(8+4\right)}{12.3}=\frac{15.12}{12.3}=\frac{5}{1}=5\)
\(\frac{15.8+15.4}{12.3}=\frac{15.\left(8+4\right)}{12.3}=\frac{5.12}{4.3}=\frac{5}{1}=5\)
\(\frac{15.8+15.4}{12.3}=\frac{31.2}{12.3}=\frac{15.6}{6.15}=\frac{7.8}{3.075}=\frac{3.9}{1.5375}\)
Rút gọn các phân số sau rồi quy đồng :
\(\frac{4.5+4.11}{8.7-4.3};\frac{-15.8+10.7}{5.6+20.3};\frac{2^4.5^2.7}{2^3.5.11.7^2}\)
phân số thứ nhất =16/11
phân số thứ hai = -5/9
phân số thứ ba = 10/77
\(\frac{3}{1.5}+\frac{3}{5.9}+\frac{3}{9.13}+...+\frac{3}{21.25}\)
\(\frac{3}{1.5}+\frac{3}{5.9}+\frac{3}{9.13}+......+\frac{3}{21.25}\)
\(=\frac{3}{4}\left(\frac{4}{1.5}+\frac{4}{5.9}+\frac{4}{9.13}+.....+\frac{4}{21.25}\right)\)
\(=\frac{3}{4}\left(1-\frac{1}{5}+\frac{1}{5}-\frac{1}{9}+......+\frac{1}{21}-\frac{1}{25}\right)\)
\(=\frac{3}{4}\left(1-\frac{1}{25}\right)\)
\(=\frac{3}{4}.\frac{24}{25}\)
\(=\frac{18}{25}\)
\(4A=3-\frac{1}{5}+\frac{3}{5}-\frac{3}{9}+\frac{3}{9}-\frac{3}{13}+...+\frac{3}{21}-\frac{3}{25}\)\(\frac{3}{25}\)
\(4A=3-\frac{3}{25}\)
\(4A=\frac{72}{25}\)
\(A=\frac{18}{25}\)
k minh ha
\(giải:\)
\(\frac{3}{1.5}+\frac{3}{5.9}+\frac{3}{9.13}+...+\frac{3}{21.25}\)
\(=3\left(\frac{1}{1.5}+\frac{1}{5.9}+\frac{1}{9.13}+...+\frac{3}{21.25}\right)\)
\(=\frac{3}{4}\left(\frac{4}{1.5}+\frac{4}{5.9}+\frac{4}{9.13}+...+\frac{4}{21.25}\right)\)
\(=\frac{3}{4}\left(\frac{1}{1}-\frac{1}{5}+\frac{1}{5}-\frac{1}{9}+\frac{1}{9}-\frac{1}{13}+...+\frac{1}{21}-\frac{1}{25}\right)\)
\(=\frac{3}{4}\left(1-\frac{1}{25}\right)\)
\(=\frac{3}{4}.\frac{24}{25}\)
\(=\frac{18}{25}\)
\(\frac{2}{1.5}+\frac{2}{5.9}+\frac{2}{9.13}+...+\frac{2}{95.99}\)
\(\frac{2}{1.5}+\frac{2}{5.9}+\frac{2}{9.13}+...+\frac{2}{95.99}\)
\(=\frac{1}{2}.\left(\frac{4}{1.5}+\frac{4}{5.9}+...+\frac{4}{95.99}\right)\)
\(=\frac{1}{2}.\left(1-\frac{1}{5}+\frac{1}{5}-\frac{1}{9}+...+\frac{1}{95}-\frac{1}{99}\right)\)
\(=\frac{1}{2}.\left(1-\frac{1}{99}\right)\)
\(=\frac{1}{2}.\frac{98}{99}\)
\(=\frac{49}{99}\)
Chúc cậu học tốt !!!