(I):a×b=36
(II):b×c=13
(III):a-c=6
Daca impartim expresia (I) la (II) avem:
(a×b)/(b×c)=36/13
a/c=36/13
a=36×c-13
=>36×c-13-c=6
35×c=18
c=18/36=9/18=1/2
a=36×1/2-13=18-13=5
b=36/a=36/5