1. a+b+c=130
a=2b => b=a/2
a=c-5 => c=a+5
Calculam totul in a, deci a + a/2 + (a+5) = 130 => 2a + a/2 = 130-5=125 =>
5a/2 = 125 => 5a = 250 => a = 50
b = a/2 => b = 50/2 = 25
c = a+5 => c = 50 + 5 = 55
Deci a=50, b=25, c=55.
2. a+b+c=130
a=b/3
c=2b
Trecem totul in b => b/3 + b + 2b = 130 => 10b/3 = 130 => 10b=390 => b=39
a=b/3=39/3=13
c=2b=2*39=78
Deci a=13, b=39, c=78.
3. a+b+c=130
a/2=2b => a=4b => b=a/4
b=c-4 => a/4=c-4 => c=a/4+4
Trecem totul in a, deci a+a/4+(a/4+4) = 130 => a + 2a/4 + 4 = 130 =>
3a/2 = 126 => 3a=252 => a=84
b=a/4 => b=84/4=21
c=b+4 => c=21+4=25
Deci a=84, b=21, c=25.