What is the solution to the system of equations: 2x + 3y = 6 and x - y = 1?
Answer: D. (1,1)
Substituting x=1 into the first equation gives 2(1) + 3y = 6, which simplifies to 3y = 4, so y = 4/3. This does not satisfy the second equation. Trying x=2 gives y=0, which satisfies both equations. The correct solution is (1,1).