To find the y-coordinate of the parabola given the quadratic equation \( y = 5x^2 + 8x + 9 \) when \( x = -3 \), we substitute \( x = -3 \) into the equation.
\[ y = 5(-3)^2 + 8(-3) + 9 \]
Now calculate each term:
- \( (-3)^2 = 9 \)
- \( 5 \times 9 = 45 \)
- \( 8 \times (-3) = -24 \)
Now substitute these values back into the equation:
\[ y = 45 - 24 + 9 \]
Now compute the sum:
\[ y = 45 - 24 = 21 \] \[ y = 21 + 9 = 30 \]
Therefore, the y-coordinate of the parabola when \( x = -3 \) is
\[ \boxed{30} \]