Răspuns :
1) [tex] \frac{2x+5}{20} = \frac{5}{4} = \frac{2x+5}{20} = \frac{25}{20} [/tex]*am amplificat 5 pe 4 cu 5 pentru a ajunge la acelasi numitor.Acum scriem relatia fara numitor.⇒ [tex]2x+5=25=2x=25-5=2x=20,x= \frac{20}{2}, x=10[/tex]
[tex] \frac{2x+5}{20} = \frac{5}{4} [/tex]
[tex]8x+20=100=\ \textgreater \ 8x=80=\ \textgreater \ x=10[/tex]
[tex]8x+20=100=\ \textgreater \ 8x=80=\ \textgreater \ x=10[/tex]