Răspuns :
a+b=67
b:a=4 rest 2
b=4a+2
a+4a+2=67
5a=67-2
5a=65
a=65:5=13
b=4a+4x13+2=52+2=54
c=2a=2x13=26
b+c=54+26=80
d=80:2=40
d-c=40-26=14
b:a=4 rest 2
b=4a+2
a+4a+2=67
5a=67-2
5a=65
a=65:5=13
b=4a+4x13+2=52+2=54
c=2a=2x13=26
b+c=54+26=80
d=80:2=40
d-c=40-26=14