数学

nevermindband

If the prime number p and t are the only prime factors of the integer m,is m a multiple of p^2*t
1)m has more than 9 positive factors.
2)m is a multiple of p^3.
答案是 B


Store s sold a total of 90 copies of a certain book during the seven days of last week,and it sold different numbers of copies on any two of the days.If for the seven days store s sold the greatest number of copies on Saturday and the second greatest number of copies on Friday,did Store s sell more than 11 copies on Friday?
1)Last week Store s sold 8 copies of the book on Tuesday.
2)Last week Store s sold 38 copies of the book on Saturday.
答案是  B


Is xy>0?
1)x-y>-2
2)x-2y<-6
答案是 C


The figure shows the top side of a circular medallion made of a circular piece of colored glass surrounded by a metal frame,represented by the shaded region.If the radius of the medallion is r centimeters and the width of the metal frame is  s centimeters,then in terms of s and r,what is the area of the metal frame,in square centimeters?
答案是  E.
各位帮帮忙,,,,这些题我接不出来,,,希望把解题步骤写出来

lovesiqi4665

If the prime number p and t are the only prime factors of the integer m,is m a multiple of p^2*t
1)m has more than 9 positive factors.
2)m is a multiple of p^3.
答案是 B

设ｍ＝ｐ＾ａ＊ｔ＾ｂ
它的ｐｏｓｉｔｉｖｅ　ｆａｃｔｏｒ有（ａ＋１）（ｂ＋１）个。
如果ａ＝１，ｂ＞４，则ｍ　ｉｓ　ｎｏｔ　ａ　ｍｕｌｔｉｐｌｅ　ｏｆ　ｐ＾２＊ｔ
ｉｆ　ａ＞１，ｓｕｆｆｉｃｉｅｎｔ。所以不选Ａ　因为ｂ＞＝１．所以选Ｂ

lovesiqi4665

第2个题。
第一问随便列下就能算出来都行。不如周一到周日一次是1.2.3.8.9.63.4或者1.2.3.8.12.60.4
第二问。如果周五是小于或者等于11.即使他是最大的11.那么除了周五周六必须卖出41本以上。包含41.但是从10+9+8+7+6=40看出最多卖40本。。所以b是对的。必须大于11本。

michellehoS

第3题目
联立两个条件，1）变形为y-x<2,两个式子相加得-y<-4即y>4;又因为x-y>-2，所以x必须大于2，所以xy>0

steinlala

后面两题都是prep的原题诶。
就是一个大圆包着一个小圆，求小圆和大圆夹住的面积。
大圆半径是r，小圆半径是r-s
然后后面就是面积相减，应该是  派s(2r-s)

steinlala

第二题也是prep原题。