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Etiennne is graphing the quadratic equat...

Etiennne is graphing the quadratic equation `y=x^(2)-8x-48`. He substtitute 0 for x and finds that the y-intercept of the graph is-48. Next, he wants to plot the x-intercepts of the graph, so he rewrites the equation in a different form. Assuming he rewrote the equations correctly and the equation reveals the x-intercepts, which of the following Etienne's new equations?

A

`Y=(x-8)^(2)-16`

B

`y=(x-8)^(2)+16`

C

`y=(x-8)(x+6)`

D

`y=(x-12)(x+4)`

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we need to rewrite the quadratic equation \( y = x^2 - 8x - 48 \) in a form that reveals the x-intercepts. Here’s how we can do it step by step: ### Step 1: Set the equation to find x-intercepts To find the x-intercepts, we set \( y = 0 \): \[ 0 = x^2 - 8x - 48 \] ### Step 2: Rearrange the equation This gives us the quadratic equation: \[ x^2 - 8x - 48 = 0 \] ### Step 3: Factor the quadratic equation Next, we need to factor the quadratic expression. We are looking for two numbers that multiply to \(-48\) (the constant term) and add to \(-8\) (the coefficient of \(x\)). The numbers that satisfy this are \(-12\) and \(4\). So we can rewrite the equation: \[ x^2 - 12x + 4x - 48 = 0 \] ### Step 4: Group the terms Now, we can group the terms: \[ (x^2 - 12x) + (4x - 48) = 0 \] ### Step 5: Factor by grouping Factoring out the common terms from each group: \[ x(x - 12) + 4(x - 12) = 0 \] Now we can factor out \((x - 12)\): \[ (x - 12)(x + 4) = 0 \] ### Step 6: Solve for x-intercepts Setting each factor to zero gives us the x-intercepts: \[ x - 12 = 0 \quad \Rightarrow \quad x = 12 \] \[ x + 4 = 0 \quad \Rightarrow \quad x = -4 \] Thus, the x-intercepts are \( (12, 0) \) and \( (-4, 0) \). ### Final Answer Etienne's new equation that reveals the x-intercepts is: \[ (x - 12)(x + 4) = 0 \]

To solve the problem, we need to rewrite the quadratic equation \( y = x^2 - 8x - 48 \) in a form that reveals the x-intercepts. Here’s how we can do it step by step: ### Step 1: Set the equation to find x-intercepts To find the x-intercepts, we set \( y = 0 \): \[ 0 = x^2 - 8x - 48 \] ...
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Knowledge Check

  • What is the y- intercept of the line by the equation 7x - 3y = 21 ?

    A
    `-7`
    B
    `-7/3`
    C
    `7/3`
    D
    `7`
  • The graph of the equation y=x^(3)+5x+1

    A
    Does not intersect the x-axis
    B
    intersects the x-axis at one and only one point
    C
    intersects the x-axis at exactly three points
    D
    intersects the x-axis at more than three points.
  • If the graph of the equation y=5x+3 is shifted down 4 units, what is the x-intercept of the new line?

    A
    `-1`
    B
    `(1)/(5)`
    C
    `1`
    D
    `(5)/(4)`
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