Răspunsuri

2014-05-18T18:46:39+03:00
A + a:2 + 2a = 140
2a + a + 4a = 280
7a = 280 
a = 280:7
a = 40
Bafta!
1 5 1
2014-05-18T18:48:08+03:00
N+n/2+2n=140
n*(1+1/2+2)=140
n*(7/2)=140 => n=140/(7/2)
n=140*2/7, n=40