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Calculeaza valoarea expresiei E=a+4b+5c-719, daca a+6b=2b+c, iar c =120.

Răspuns :

a+4b=120 120+5*120-719 120+600-719 720-719 1
E=a+4b+5c-719...
a+6b=2b +c.... , c=120
a+6b=2b+120
a+6b-2b=120
a+4b=120
E=a+4b+5c-719
E=120+5*120 - 719
E=120+600- 719
E=720-719
E=1