inca o problema:
x+y-z=39
x+y=96
y-z=12
va rog


Răspuns :

x+y-z=39

x+y=96

y-z=12

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x=? y=? z=?

-----------------

x+y-z=39

96-z=39

z=96-39

z=57

x+y-z=39

x+12=39

x=39-12

x=27

x+y-z=39

57+y-27=39

30+y=39

y=39-30

y=9

Seara buna!