6
algebra

Determine the value of aa if the lines ax+2y=6ax + 2y = 6 and 3xy=43x - y = 4 are perpendicular.

A

23\frac{2}{3}

B

23-\frac{2}{3}

C

66

D

6-6

Correct Answer: A

Choice A is the correct answer. Product of slopes is -1.

  1. Slope 1: a/2-a/2.
  2. Slope 2: 3/(1)=3-3/(-1) = 3.
  3. Condition: (a/2)×3=1(-a/2) \times 3 = -1.
  4. Solve: 3a/2=13a=2a=2/3-3a/2 = -1 \rightarrow 3a = 2 \rightarrow a = 2/3.

💡 Strategic Tip: Or: Slope 2 is 3. Perpendicular slope is -1/3. Set a/2=1/3a/2=1/3a=2/3-a/2 = -1/3 \rightarrow a/2 = 1/3 \rightarrow a = 2/3.

Choice B is incorrect because sign error. Choice C is incorrect.Choice D is incorrect.