Question

5.a+15.b=45, 7.a+15.b=51

Answer 1

Răspuns:

sa inteleg ca"." inseamna "×"? Pai daca e asa atunci rezolvarea o sa fie asa:

5a+15b=45

5(a+3b)=45

a+3b=9 => a=9-3b

7a+15b=51

7(9-3b)+15b=51

63-21b+15b=51

-6b=51-63

-6b=-12

b=-12/-6

b=2

a=9-3b=9-3×2=3