ABC triunghiul
AB=a
AC=b
BC=a+9
BC=2b
P=a+b+a+9=>P=2a+b+9=>2a+b+9=99=>2a+b=90
P=a+b+2b=>P=a+3b=>a+3b=99
[tex] \left \{ {{2a+b=90} \atop {a+3b=99} \right. [/tex]
Inmultim relatia (1) cu 3
[tex] \left \{ {{6a+3b=270} \atop {a+3b=99}} \right. [/tex]
FAcem diferenta ceor doua ecuatii
5a=171=>a=171/5
BC=a+9=>BC=171/5+9=216/5
BC=2b=>b=(216/5)/2
MAi verifica tu calculele ca e posibil sa fi gresit pe undeva
