\[ y = -2 \cdot (-1) + 9 = 2 + 9 = 11 \]
\[ y = -2 \cdot 2 + 9 = -4 + 9 = 5 \]
\[ y = -2 \cdot 2.5 + 9 = -5 + 9 = 4 \]
\[ y = -2 \cdot 7 + 9 = -14 + 9 = -5 \]
Ответ: 1) y = 11; 2) y = 5; 3) y = 4; 4) y = -5