Choice C is the correct answer. Let's rearrange the first equation.

Step 1: From $y = 7x - 3$: $-7x + y = -3$

Multiply by -2: $14x - 2y = 6$

This is exactly the second equation!

Conclusion: Infinitely many solutions (same line)

💡 Strategic Tip: Converting between forms (slope-intercept ↔ standard) often reveals identical equations.

Choice A is incorrect because no solution requires parallel lines with different constants.

Choice B is incorrect because one solution requires different slopes.

Choice D is incorrect because linear systems cannot have exactly three solutions.