Question

Daca a+b=-1/2 si b+c =2/3 , atunci a+2b+c=...

Answer 1

a + b      = - 1/2      +
      b + c=   2/3
a +2b+c = $\frac{2}{3}-\frac{1}{2}=\frac{4-3}{6}=\frac{1}{6}$