To determine which quadratic equation has only one distinct solution, we need to check for equations that can be factored into the form \((x - r)^2 = 0\), where \(r\) is a repeated root.
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\(x^2 + 4x + 4 = 0\)
This can be factored as \((x + 2)(x + 2) = (x + 2)^2 = 0\).
Distinct solution: \(x = -2\) (one solution). -
\(x^2 - 5x + 4 = 0\)
This can be factored as \((x - 1)(x - 4) = 0\).
Distinct solutions: \(x = 1\) and \(x = 4\) (two solutions). -
\(x^2 - 4 = 0\)
This can be factored as \((x - 2)(x + 2) = 0\).
Distinct solutions: \(x = 2\) and \(x = -2\) (two solutions). -
\(x^2 + 5x + 4 = 0\)
This can be factored as \((x + 1)(x + 4) = 0\).
Distinct solutions: \(x = -1\) and \(x = -4\) (two solutions).
The equation that has only one distinct solution is:
\(x^2 + 4x + 4 = 0\).