( - 1 ; 2 )
- 6 + 2b = 5a
- 2a - 12 = b
2a = - b - 12
a = -0,5b - 6
- 6 + 2b = - 2,5b - 30
4,5b = - 24
b = - 240/45 = - 48/9 = - 5 3/9 = - 5 1/3
a = - ( 1/2)•( - 48/9 ) - 6 = 48/18 - 6 = 24/9 - 54/9 = - 30/9 = - 10/3 = - 3 1/3
Ответ а = - 3 1/3 ; b = - 5 1/3