If x2 + y2 = 29, what is the value of (x - y)2 ?

(1) xy = 10

(2) x = 5

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.

##### 考题讲解

（1）  已知xy=10和~$x^2+y^2=29$~，所以~$x^2+2xy+y^2=10*2+29=49$~，题目得解。

（2）    仅知道x=5，不能确定y的值，也就不能计算~$(x-y)^2$~的值。