Răspuns :
[tex]\it m=4f\\ \\ t=m+f-5=4f+f-5=5f-5\\ \\ t+m+f=85 \Rightarrow 5f-5+4f+f=85 \Rightarrow 10f=90 \Rightarrow f=9ani\\ \\ m=4\cdot9=36ani\\ \\ t=5\cdot9-5=40\ ani[/tex]
[tex]\it m=4f\\ \\ t=m+f-5=4f+f-5=5f-5\\ \\ t+m+f=85 \Rightarrow 5f-5+4f+f=85 \Rightarrow 10f=90 \Rightarrow f=9ani\\ \\ m=4\cdot9=36ani\\ \\ t=5\cdot9-5=40\ ani[/tex]