\(A=\frac{3.5.7.11.13.37-10101}{1212120+40404}\)
\(=\frac{15015.37-273.37}{32760.37+1093.37}\)
\(=\frac{14742.37}{33853.37}\)
\(=\frac{14742}{33853}\)
\(A=\frac{3\cdot5\cdot7\cdot11\cdot13\cdot37-10101}{1212120+40404}\)
\(A=\frac{(3\cdot7\cdot11\cdot13\cdot37)\cdot5-10101}{10101\cdot120+10101\cdot4}\)
\(A=\frac{10101\cdot5-10101}{10101\cdot(120+4)}\)
\(A=\frac{10101\cdot(5-1)}{10101\cdot(120+4)}=\frac{4}{124}=\frac{1}{31}\)
Trả lời : Bài này là thi HSG đó bạn :
\(A=\frac{3.5.7.11.13.37-10101}{1212120+40404}\)
\(A=\frac{3.5.7.11.13.37-3.7.13.37}{2^3.3^2.5.13.37+2^2.3.7.13.37}\)
\(A=\frac{3.7.13.37.\left(5.11-1\right)}{2^2.3.7.13.37.\left(2.3.5+1\right)}\)
\(A=\frac{54}{124}=\frac{27}{62}\)
\(\Rightarrow A=\frac{27}{62}\)
Hok_Tốt
#Thiên_Hy
Nhầm tí :v
\(A=\frac{3\cdot5\cdot7\cdot11\cdot13\cdot37-10101}{1212120+40404}\)
\(A=\frac{5\cdot11\cdot10101-10101}{10101\cdot120+10101\cdot4}\)
\(A=\frac{10101\cdot(5\cdot11-1)}{10101\cdot(120+4)}=\frac{10101\cdot54}{10101\cdot124}=\frac{54}{124}=\frac{27}{62}\)