Explicație pas cu pas:
D ∈ MN
E ∈ MT
DE || NT
[tex]\frac{MD}{DN} = 4 = > MD = 4DN[/tex]
[tex]MN = MD + DN = 4DN + DN = 5DN [/tex]
[tex]= > \frac{MD}{MN} = \frac{4DN}{5DN} = \frac{4}{5}[/tex]
DE || NT
[tex] = > \frac{MD}{MN} = \frac{ME}{MT} = \frac{DE}{NT} = \frac{4}{5}[/tex]