Determine the missing values

Given the function $Y = -2x + 3$ and $x = -3$.
Substitute $x = -3$ into the equation:

$$Y = -2(-3) + 3$$ $$Y = 6 + 3$$ $$Y = 9$$

The value for 2.1.1 is $\boxed{\text{9}}$.

Given the function $Y = -2x + 3$ and $x = 0$.
Substitute $x = 0$ into the equation:

$$Y = -2(0) + 3$$ $$Y = 0 + 3$$ $$Y = 3$$

The value for 2.1.2 is $\boxed{\text{3}}$.

Given the function $Y = -2x + 3$ and $Y = 5$.
Substitute $Y = 5$ into the equation:

$$5 = -2x + 3$$

Subtract 3 from both sides:

$$5 - 3 = -2x$$ $$2 = -2x$$

Divide by -2:

$$x = \frac{2}{-2}$$ $$x = -1$$

The value for 2.1.3 is $\boxed{\text{-1}}$.

Given the function $Y = -2x + 3$ and $Y = 17$.
Substitute $Y = 17$ into the equation:

$$17 = -2x + 3$$

Subtract 3 from both sides:

$$17 - 3 = -2x$$ $$14 = -2x$$

Divide by -2:

$$x = \frac{14}{-2}$$ $$x = -7$$

The value for 2.1.4 is $\boxed{\text{-7}}$.