a+b+c = 300
c = a+b
a = b:4 => b = 4×a
c = a+4×a = 5×a
5×a = a+b
5×a-a = b
4×a = b
inlocuim in prima ecuatie
a + 4×a + 5×a = 300
10×a = 300
a = 300:10
a = 30
b = 4×30 = 120
c = 5×30 = 150
un alt mod de rezolvare:
a |___|
b |___|___|___|___|
c |___|___|___|___|___|
avem 10 segmente egale = 300
300 : 10 = 30 ( un segment)
a = 30
b = 30×4 = 120
c = 5×30 = 150
Verificare:
30 + 120 + 150 = 300
a = 30
b = 120
c = 150
