Question 1
Joana's conclusion is not correct. She states:
- "No, because she can continue the steps even if the two groupings have no shared binomial."
In this case, Joana can still find the roots of the equation despite the lack of a common binomial after her grouping steps.
Question 2
To determine which quadratic equation has only one distinct solution, we need to find the equations that can be factored into a perfect square trinomial or an irreducible factor.
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\( x^2 - 5x + 4 = 0 \)
- Factors as \( (x - 1)(x - 4) = 0 \) → Solutions: \( x = 1, x = 4 \) (two distinct solutions).
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\( x^2 + 4x + 4 = 0 \)
- Factors as \( (x + 2)(x + 2) = 0 \) → Solution: \( x = -2 \) (one distinct solution).
-
\( x^2 + 5x + 4 = 0 \)
- Factors as \( (x + 1)(x + 4) = 0 \) → Solutions: \( x = -1, x = -4 \) (two distinct solutions).
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\( x^2 - 4 = 0 \)
- Factors as \( (x - 2)(x + 2) = 0 \) → Solutions: \( x = 2, x = -2 \) (two distinct solutions).
Thus, the equation that has only one distinct solution is:
- \( x^2 + 4x + 4 = 0 \).