单选题
【正确答案】
C
【答案解析】Draw a diagram.
[*]
The minute hand, of course, is pointing right at 4. The hour hand, however, is not pointing at 11. It was pointing at 11 at 11:00, 20 milnutes, or [*] hour, ago. The hour hand is now one-third of the way between 11 and 12, so there are 20 degrees between the hour hand and 12 and another 120 degrees to 4, a total of 140 degrees. The columns are equal (C).
[*]
The minute hand, of course, is pointing right at 4. The hour hand, however, is not pointing at 11. It was pointing at 11 at 11:00, 20 milnutes, or [*] hour, ago. The hour hand is now one-third of the way between 11 and 12, so there are 20 degrees between the hour hand and 12 and another 120 degrees to 4, a total of 140 degrees. The columns are equal (C).
【正确答案】
C
【答案解析】This one is easier than it looks. Don't try to factor. Don't solve. Just add 2x to both sides of the given equation to get that x2 -7 = x. The columns are equal (C).