2)
a=mere are Andrei
b=mere are Barbu
c=mere are Calin
a+b+c=22
b=2a
c=b-3
c=2a-3
a+2a+2a-3=22
5a=22+3
5a=25
a=25:5
a=5
b=5*2=10
c=5*2-3=7
3)
[tex]x=(\sqrt{2}+ \sqrt{72}):( \sqrt{18}+ \sqrt{50}- \sqrt{32})= \\ ( \sqrt{98}):( \sqrt{32})= \\ \sqrt{98:32}= \\ \sqrt{3,0625}=1,75[/tex]
Raspus final: x=1,75