6
algebra

What is true about this system? {4x2y=68x4y=10\begin{cases} 4x - 2y = 6 \\ 8x - 4y = 10 \end{cases}

A

The lines intersect at exactly one point

B

The lines are identical

C

The lines are parallel but not identical

D

The lines are perpendicular

Correct Answer: C

Choice C is the correct answer. Let's check the relationship.

Step 1: Multiply the first equation by 2: 2(4x2y)=2(6)2(4x - 2y) = 2(6)8x4y=128x - 4y = 12

Step 2: Compare with the second equation:

  • Our result: 8x4y=128x - 4y = 12
  • Given: 8x4y=108x - 4y = 10

Left sides match, but 12 eq1012 \ eq 10Parallel but not identical

Conclusion: No solution (parallel lines that never meet)

💡 Strategic Tip: "Parallel but not identical" is another way of saying "no solution."

Choice A is incorrect because intersecting at one point requires different slopes.

Choice B is incorrect because identical lines would have 12=1012 = 10, which is false.

Choice D is incorrect because both lines have the same slope (2), not perpendicular slopes.