Which of the following equations has exactly the same solutions as (x−7)(x+9)=0

?(1 point)
Responses

x2=2x−63
x squared equals 2 x minus 63

x2=−2x+63
x squared equals negative 2 x plus 63

x2+2x=−63
x squared plus 2 x equals negative 63

x2−2x−63=0

1 answer

To find out which of the given equations has exactly the same solutions as \((x−7)(x+9)=0\), we first determine the solutions to the original equation.

Setting \((x−7)(x+9)=0\) gives us the solutions:

  1. \(x - 7 = 0 \Rightarrow x = 7\)
  2. \(x + 9 = 0 \Rightarrow x = -9\)

Thus, the solutions to the equation \((x−7)(x+9)=0\) are \(x = 7\) and \(x = -9\).

Now, we will examine each of the given equations to see if they yield the same solutions.

  1. \(x^2 = 2x - 63\):
    Rearrange to standard form:
    \[ x^2 - 2x + 63 = 0 \]
    The solutions can be found using the quadratic formula, and they will not yield 7 or -9.

  2. \(x^2 = -2x + 63\):
    Rearrange to standard form:
    \[ x^2 + 2x - 63 = 0 \]
    This can be factored:
    \((x - 7)(x + 9) = 0\)
    This equation has solutions \(x = 7\) and \(x = -9\).

  3. \(x^2 + 2x = -63\):
    Rearrange to standard form:
    \[ x^2 + 2x + 63 = 0 \]
    The solutions do not match 7 or -9.

  4. \(x^2 - 2x - 63 = 0\):
    This factors into:
    \((x - 9)(x + 7) = 0\)
    The solutions will be \(x = 9\) and \(x = -7\), which do not match.

The only equation that has the exact same solutions \(x = 7\) and \(x = -9\) is:

\(x^2 + 2x - 63 = 0\).