GMAT考试

【单选题】For any numbers w and z, w·z=w³z(8-w²). If both z and w·z are positive numbers, which of the following could be a value of w
A、9
B、3
C、0
D、-2
E、-9

网考网参考答案：E
网考网解析：
The most direct approach here is probably to plug in the answers and see which one gives a positive value for w·z. A and B are out because (8-w 2 ) results in a negative number while w 3 z is positive, C is out because 0 is not a positive number, D is out because w 3 z is negative while (8-w 2 ) is positive; only E meets the conditions, because both (8-w 2 ) and w 3 z are negative, yielding a positive value for w·z. document.getElementById("warp").style.display="none"; document.getElementById("content").style.display="block"; 查看试题解析出处>>