2016:7=288(kg de nutret consuma zilnic 2 zimbri si 8 zebre )
notam cu a zimbri si cu b zebrele
2a+8b=288. dar a=4b
8b+8b=288. 16b=288
b=288:16. b=18
o zebra mananca 18 kg nutret zilnic
a=4×b. a=4×18. a=72
un zimbru mananca 72 kg nutret zilnic
proba :
(2×72+8×18)×7=144+144
=288×7=2016