daca b-c =15 si ab-ac =-510 atunci a = ? Daca a =-27 si ab +ac =-837 atunci b+c =?

1. ab-ac=-510⇒a(b-c)= -510 ⇒ a*15 =-510 ⇒a= - 34                                        2. ab+ac= - 837 ⇒a( b+c) =- 837⇒-27(b+c) = -837 ⇒b+c= 837/27 ⇒b+c = 31