Question

[nguyen thi huyen trang]

tim 1 phan so bit tu so hon mau so la 215vva phan so do co gia tri la 38/57

Answer 1

[Nguyễn Minh Quang]

ta có 

\(\hept{\begin{cases}\frac{a}{b}=\frac{38}{57}\\b-a=215\end{cases}\Rightarrow\frac{b-a}{b}=\frac{57-38}{57}\Leftrightarrow\frac{215}{b}=\frac{1}{3}}\)

\(\Leftrightarrow b=645\Rightarrow a=430\Rightarrow\)phân số là \(\frac{430}{645}\)