Đặt \(A=\frac{3\cdot7\cdot13\cdot37\cdot39-10101}{505050-70707}\)
\(A=\frac{\left(3\cdot7\cdot13\cdot37\right)\cdot39-10101\cdot1}{50\cdot10101+7\cdot10101}\)
\(A=\frac{10101\cdot39-10101\cdot1}{10101\cdot\left(50+7\right)}\)
\(A=\frac{10101\cdot\left(39-1\right)}{10101\cdot57}\)
\(A=\frac{10101\cdot38}{10101\cdot57}\)
\(A=\frac{38}{57}=\frac{38:19}{57:19}=\frac{2}{3}\)