单选题 What is the value of x?(1) 4x+1 + 4x = 320(2) x2 = 9

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.

【正确答案】 A

【答案解析】Determine the value of x.(1) If 4x+1 + 4x = 320, then 4x(4 + 1) = 320, from which 4x = 64 and x = 3; SUFFICIENT.(2) If a2 = 9, then x = -3 or x = 3; NOT sufficient.The correct answer is A；statement 1 alone is sufficient.