Răspuns :
4c+6a=440
1a=15+1c
4c+6(15+c)=440
4c+90+6c=440
10c+90=440
10c=440-90
10c=350
c=350:10
c=35
a=15+35
a=50
1a=15+1c
4c+6(15+c)=440
4c+90+6c=440
10c+90=440
10c=440-90
10c=350
c=350:10
c=35
a=15+35
a=50