请教天山-9-5

woodruff1

Q5:

If (y+3)(y-1) – (y-2)(y-1) = r(y-1), what is the value of y?

(1) r2 = 25

(2) r = 5

A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.

B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.

C. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is

sufficient.

D. EACH statement ALONE is sufficient.

E. Statements (1) and (2) TOGETHER are NOT sufficient.

Answer:E

请问其他XDJM对此答案是否有异议？

piqiuwawa

题目化简后为 5(y-1)=r(y-1),

B 选项中r=5 时, y 可以取任意数,所以不充分

A 选项中r=5 或-5, 当r= -5 时,可求得Y= 1, 所以 A 应该正确啊, 为什么选 E 呢 ?

哪位NN能帮忙解答一下

jhiiool

A选项中R本身就有两个值了，当R=-5的时候确实Y只有一个值，但R=5时Y却有无数个解，1+无数=无数；当然不是确定的、唯一的解

选E