Răspuns :
a+a+1+a+2+a+3+a+4=30
5a+10=30
5a=20
a=20:5
a=4
b=a+1=5
c=a+2=6
d=a+3=7
e=a+4=8
4+5+6+7+8=30
2)
c:b=3 rest 4
c=3b+4
b=a-c
c=b+16
3b+4=b+16
3b-b=16-4
2b=12
b=6
c=6+16=22
a=6+22=28
5a+10=30
5a=20
a=20:5
a=4
b=a+1=5
c=a+2=6
d=a+3=7
e=a+4=8
4+5+6+7+8=30
2)
c:b=3 rest 4
c=3b+4
b=a-c
c=b+16
3b+4=b+16
3b-b=16-4
2b=12
b=6
c=6+16=22
a=6+22=28