What is the value of xy ?
(1) x + y = 10
(2) x - y = 6
Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
EACH statement ALONE is sufficient.
Statements (1) and (2) TOGETHER are NOT sufficient.
题目分析:
(1) 仅有x+y=10一个方程无法解得x和y的值,也不能求得xy的值。
(2) 仅有x-y=6一个方程无法解得x和y的值,也不能求得xy的值。
结合条件1和条件2,可以解得x=8,y=2,则xy=16,题目得解。
因此,本题答案为(C),两个条件结合起来才能解题,任何单独一个均不行