Răspuns :
a+b+c=625
b-a=2⇔-a=2-b *-1⇔a=b-2
b-c=12⇔-c=12-b *-1⇔c=b-12
b-2+b+b-12=625
3b-14=625
3b=625+14
3b=639
b=639:3
b=213
a=213-2=211
a=211
c=213-12
c=201
m:n=5
m-n=64⇔m=64+n
(64+n):n=5
64/n+n/n=5
64/n+1=5
64/n=5-1
64/n=4
4n=64
n=64:4
n=16
m=64+16
m=80
b-a=2⇔-a=2-b *-1⇔a=b-2
b-c=12⇔-c=12-b *-1⇔c=b-12
b-2+b+b-12=625
3b-14=625
3b=625+14
3b=639
b=639:3
b=213
a=213-2=211
a=211
c=213-12
c=201
m:n=5
m-n=64⇔m=64+n
(64+n):n=5
64/n+n/n=5
64/n+1=5
64/n=5-1
64/n=4
4n=64
n=64:4
n=16
m=64+16
m=80