Răspuns :
a + b + c = 170
b = 2a
c - b = 20 ⇒ c = b + 20
-------------------------------------
a |-------|
b |-------|-------| } 170
c |-------|-------|-20-|
170 - 20 = 150
150 : 5 segm = 30
a = 30
b = 30 × 2 = 60
c = 60 + 20 = 80
Fie x, y, z cele 3 numere
x+y+z=170
y=2x =>
[tex]x = \frac{y}{2} [/tex]
z-y=20 => z=20+y
Inlocuim cele 2 in prima ecuatie
[tex] \frac{y}{2} + y + 20 + y = 170[/tex]
Amplificam cu 2 si scapam de numitor
[tex]y + 4y + 40 = 340[/tex]
5y=300
y=60
[tex]x = \frac{y}{2} = \frac{60}{2} = 30[/tex]
z=20+y=20+60=80
x+y+z=170
y=2x =>
[tex]x = \frac{y}{2} [/tex]
z-y=20 => z=20+y
Inlocuim cele 2 in prima ecuatie
[tex] \frac{y}{2} + y + 20 + y = 170[/tex]
Amplificam cu 2 si scapam de numitor
[tex]y + 4y + 40 = 340[/tex]
5y=300
y=60
[tex]x = \frac{y}{2} = \frac{60}{2} = 30[/tex]
z=20+y=20+60=80