Question

Answer 1

Xét tam giác QPR có EF//QR:

\(\dfrac{PE}{EQ}=\dfrac{PF}{FR}\Leftrightarrow\dfrac{16}{EQ}=\dfrac{20}{15}\Leftrightarrow EQ=16:\dfrac{20}{15}=12\left(cm\right)\left(hệquảđlta-lét\right)\)

\(x=PE+EQ=16+12=28\left(cm\right)\)

 

Xét tam giác ABC có MN//BC :

\(\dfrac{x}{NC}=\dfrac{AM}{MB}\Leftrightarrow\dfrac{x}{9}=\dfrac{17}{10}\Rightarrow x=\dfrac{17}{10}.9=15,3\left(cm\right)\) ( hệ quả đl ta-lét)