Question

Graphs of Quadratic Equations Practice
Complete this assessment to review what you’ve learned. It will not count toward your grade.
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Question
Given the quadratic equation y=5x2+8x+9
, solve for the y-coordinate of the parabola when x=−3
.(1 point)
(−3
,
)
Remaining Attempts : 3

Answer 1

To find the y-coordinate of the parabola given the quadratic equation \( y = 5x^2 + 8x + 9 \) when \( x = -3 \), we need to substitute \( -3 \) into the equation.

1. Substitute \( x = -3 \) into the equation:
\[
y = 5(-3)^2 + 8(-3) + 9
\]

2. Calculate \( (-3)^2 \):
\[
(-3)^2 = 9
\]

3. Substitute this back into the equation:
\[
y = 5(9) + 8(-3) + 9
\]

4. Calculate \( 5(9) \):
\[
5(9) = 45
\]

5. Calculate \( 8(-3) \):
\[
8(-3) = -24
\]

6. Now, put everything back into the equation:
\[
y = 45 - 24 + 9
\]

7. Combine the numbers:
\[
45 - 24 = 21
\]
\[
21 + 9 = 30
\]

So, the y-coordinate when \( x = -3 \) is \( 30 \).

The final answer is:
\[
(-3, 30)
\]