8

Set 2: Systems of Equations (Advanced)

Explanation

Answer: B

Which value of kk makes the system have no solution? {y=2x+7y=kx+3\begin{cases} y = -2x + 7 \\ y = kx + 3 \end{cases}

A.

k=7k = 7

B.

k=2k = -2

✓ Correct
C.

k=3k = 3

D.

k=2k = 2

Detailed Explanation

Choice B is correct. Choice B is the correct answer. For no solution, we need parallel lines. Analysis: - First line: slope = -2, y-intercept = 7 - Second line: slope = kk, y-intercept = 3 Condition for parallel lines: - Same slope: k=2k = -2 - Different y-intercepts: 7 ≠ 3 ✓ (already different) With k=2k = -2, both lines have slope 2-2 but different y-intercepts, making them parallel with no intersection. Strategic Tip: For no solution in slope-intercept form, match the slopes but keep different intercepts. Choice A is incorrect because k=7k = 7 gives different slopes (-2 and 7), resulting in one solution. Choice C is incorrect because k=3k = 3 gives different slopes, resulting in one solution. Choice D is incorrect because k=2k = 2 gives different slopes, resulting in one solution.

Key Steps:

The correct answer is k=2k = -2

Why others are wrong:
A: Choice A is incorrect and may result from a calculation error.
C: Choice C is incorrect and may result from a calculation error.
D: Choice D is incorrect and may result from a calculation error.

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