\(\frac{2}{3}\)

\(\frac{3.7.13.37.19-10101}{505050+70707}\)=\(\frac{10101.39-10101}{10101.50+10101.7}\)=\(\frac{10101.\left(39-1\right)}{10101.\left(50+7\right)}\)=\(\frac{38}{57}\)=\(\frac{2}{3}\)

\(\frac{3.7.13.37.39-10101}{505050+70707}\)

\(=\frac{\left(3.7.13.37\right).39-10101}{50.10101+7.10101}\)

\(=\frac{10101.39-10101.1}{\left(50+7\right).10101}\)

\(=\frac{\left(39-1\right).10101}{57.10101}\)

\(=\frac{38.10101}{57.10101}\)

\(=\frac{38}{57}=\frac{38:19}{57:19}=\frac{2}{3}\)

a) \(\frac{6.9-2.17}{63.3-119}=\frac{54-34}{189-119}=\frac{20}{70}=\frac{2}{7}\)

b)Mình làm ở đây rồi nhá:  Câu hỏi của Lady Ice - Học và thi online với HOC24

3.7.13.37.39-10101/505050+70707

=393939-10101/505050+70707

=10101.39-10101/505050+70707

=10101(39-1)/10101.50 +70707

=10101.38/10101+70707

=38+70707=70745

Đặt \(A=\frac{3\cdot7\cdot13\cdot37\cdot39-10101}{505050-70707}\)

\(A=\frac{\left(3\cdot7\cdot13\cdot37\right)\cdot39-10101\cdot1}{50\cdot10101+7\cdot10101}\)

\(A=\frac{10101\cdot39-10101\cdot1}{10101\cdot\left(50+7\right)}\)

\(A=\frac{10101\cdot\left(39-1\right)}{10101\cdot57}\)

\(A=\frac{10101\cdot38}{10101\cdot57}\)

\(A=\frac{38}{57}=\frac{38:19}{57:19}=\frac{2}{3}\)

p/s đầu bằng 1/5, còn cái kai là 0.66666667

Ta có:

\(\frac{3.7.13.37.39-10101}{505050-70707}=\frac{10101.39-10101}{505050-70707}=\frac{10101\left(39-1\right)}{10101\left(50-7\right)}=\frac{39-1}{50-7}=\frac{38}{43}\)

38/43 đó

=-1

=2/5

=38/43

= 3/2

_{10101(39-1)/10101(50+7)=2/3 bn}