【正确答案】 C

【答案解析】Add the equations. [*] Since 2y = 0, y = 0. **Use TACTIC 4. Could y = 0? In each equation, if y = 0, then x = -5. So, y can equal 0. Eliminate Choices A and B, and either guess between Choices C and D or continue. Must y = 0? Yes, when you have two linear equations in two variables, there is only one solution, so nothing else is possible.