Features of Graphs of Quadratic Equations Quick Check

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Question
Use any method to locate the zeros of y=−3x2+12x+15.(1 point)
Responses

(0,15)
left parenthesis 0 comma 15 right parenthesis

There are no zeros.
There are no zeros.

(−1,0)(5,0)
left parenthesis negative 1 comma 0 right parenthesis left parenthesis 5 comma 0 right parenthesis

(1,0)(−5,0)
left parenthesis 1 comma 0 right parenthesis left parenthesis negative 5 comma 0 right parenthesis
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1 answer

To find the zeros of the quadratic equation \( y = -3x^2 + 12x + 15 \), we can set the equation to zero and solve for \( x \):

\[ -3x^2 + 12x + 15 = 0 \]

To simplify the equation, we can divide everything by -3:

\[ x^2 - 4x - 5 = 0 \]

Next, we can factor the quadratic:

\[ (x - 5)(x + 1) = 0 \]

Setting each factor to zero gives us the possible solutions:

\[ x - 5 = 0 \quad \Rightarrow \quad x = 5 \] \[ x + 1 = 0 \quad \Rightarrow \quad x = -1 \]

Thus, the zeros of the quadratic equation are \( x = 5 \) and \( x = -1 \).

In coordinate notation, the zeros are:

\[ (-1, 0) \quad \text{and} \quad (5, 0) \]

Therefore, the correct response would be:

(−1, 0) and (5, 0).