Choice B is the correct answer. Let's check if one equation is a multiple of the other.

Step 1: Multiply the first equation by 2: $2(x + y) = 2(5)$$2x + 2y = 10$

This is exactly the second equation!

Step 2: Since both equations represent the same line, any point that satisfies one equation automatically satisfies the other.

Conclusion: Infinitely many solutions

Examples of solutions: $(0, 5)$, $(1, 4)$, $(2, 3)$, $(3, 2)$, $(4, 1)$, $(5, 0)$, and infinitely more.

💡 Strategic Tip: Coincident lines (same line) have infinitely many solutions.

Choice A is incorrect because no solution occurs only with parallel lines that don't overlap.

Choice C is incorrect because exactly one solution occurs only when lines intersect at a single point.

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