Let’s go through each question one by one.
Question 2 A
To determine which statement is correct regarding the situation where a squared variable expression equals a numeric expression, we focus on the scenario where the numeric expression is zero:
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Statement #1: If the numeric expression is zero, there are two solutions. (False – there can be at most one solution)
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Statement #2: If the numeric expression is zero, there is one solution. (True – \( x^2 = 0 \) gives \( x = 0 \))
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Statement #3: If the numeric expression is zero, there are no solutions. (False)
Correct Answer: Statement #2: If the numeric expression is zero, there is one solution.
Question 3 A
To solve \( x^2 = 100 \) by inspection, we take the square root of both sides:
- \( x = \sqrt{100} = 10 \)
- \( x = -\sqrt{100} = -10 \)
Solutions: {10, -10}
Question 4 A
To solve the equation \( -9 + (x - 3)^2 - 4 = -4 \):
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Simplify the equation: \[ (x - 3)^2 - 9 = -4 \] \[ (x - 3)^2 = 5 \]
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Take the square root of both sides: \[ x - 3 = \pm \sqrt{5} \]
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The solutions are: \[ x = 3 + \sqrt{5} \text{ and } x = 3 - \sqrt{5} \]
None of the provided answer choices match the exact solutions derived.
If you assume approximate numbers to match the answer choices:
- \( 3 + \sqrt{5} \approx 5.236 \)
- \( 3 - \sqrt{5} \approx 0.764 \)
None of the provided options seem correct based on the mathematical solution derived.
Question 5 A
To find the values of \( x \) from \( (x + 4)(x - 2) = 0 \):
Set each factor to zero:
- \( x + 4 = 0 \) → \( x = -4 \)
- \( x - 2 = 0 \) → \( x = 2 \)
Answer: x = -4 and x = 2
Question 6 A
To solve the factored quadratic equation \( (19x - 3)(9 + x) = 0 \):
Set each factor to zero:
- \( 19x - 3 = 0 \) → \( 19x = 3 \) → \( x = \frac{3}{19} \)
- \( 9 + x = 0 \) → \( x = -9 \)
Solution set: \( x = { \frac{3}{19}, -9 } \)
Question 7 A
To solve the quadratic equation \( 84x^2 + 16x = 0 \) by factoring out the GCF:
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The GCF is \( 4x \): \[ 4x(21x + 4) = 0 \]
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Setting factors to zero:
- \( 4x = 0 \) → \( x = 0 \)
- \( 21x + 4 = 0 \) → \( 21x = -4 \) → \( x = -\frac{4}{21} \)
Solutions: The solutions are \( x = 0 \) and \( x = -\frac{4}{21} \)
Question 8 A
Jamal and George's steps seem largely correct, with Jamal solving \( x^2 + 4x - 12 = 0 \) correctly and finding \( x = -6 \) and \( x = 2 \).
George's steps, however, set the quadratic equation incorrectly. The equation \( x^2 + 4x - 5 = 7 \) should be rearranged to \( x^2 + 4x - 12 = 0 \).
Thus, Jamal’s solution is correct, while George has errors leading to incorrect factorization and solutions.
Final Notes: Ensure each answer aligns contextually based on further instructions or requirements for format.