请教天山数学第5题

renprince

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？

bfghdggf

E
由原题得出r(y-1)=r(y-1),所以得不出来

himba

我选B，当R=5时，Y可以为任意值。
就是不太确定在GMAT中，Y可以为任意值算不算充分。

equilibrium

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 ?