Răspuns :
a+b+c=70
a+b=41
b+c=43
b=43-c
a=41-b=41-(43-c)
41-43-c+43-c+c=70
41-c=70/ 70-41
c=29
b=43-29=14
a=41-14=27
a+b=41
b+c=43
b=43-c
a=41-b=41-(43-c)
41-43-c+43-c+c=70
41-c=70/ 70-41
c=29
b=43-29=14
a=41-14=27
a+b+c=70
a+b=41
b+c=43
c=70-41
C=21
b=43-29
b=14
a=41-14
a=27
27+14+29=70