Set 11: Linear Equations (Intermediate)

Choice C is correct. Choice C is the correct answer. 1. Solve System: Multiply 2 nd \neq by 2: $2x - 4 y = 20$ 2. Add to 1 st: $(3 x + 4 y) + (2 x - 4 y) = 20 + 20 \rightarrow 5 x = 40 \rightarrow x = 8$ 3. Find y: $8- 2 y = 10 \rightarrow -2 y = 2 \rightarrow y = -1$ 4. Calculate: $x + y = 8 + (-1) = 7$ Choice A is incorrect because it results from an error in the solution process. Choice C is incorrect because it results from an error in the solution process. Choice D is incorrect because it results from an error in the solution process.