For what value of does the system have infinitely many solutions?
Correct Answer: C
Choice C is the correct answer. For infinitely many solutions, the second equation must be a multiple of the first (or vice versa).
Step 1: Notice that the first equation's coefficients are double the second:
- First:
- Second:
Step 2: Divide the first equation by 2:
Step 3: For the equations to be identical:
With , both equations represent the same line, giving infinitely many solutions.
💡 Strategic Tip: For infinitely many solutions, one equation must be a scalar multiple of the other (including the constant term).
Choice A is incorrect because would make the lines parallel (no solution), not identical.
Choice B is incorrect because would make the lines parallel (no solution).
Choice D is incorrect because would make the lines parallel (no solution).