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