题目

SAT og 3道数学题,
the total daily cost c,in dollars ,of producing x units of a certain prduct is given by the function c(x)5(600x-200)/x1k,where k is a constant and x#100.if 20 units were prducud yesterday for a total cost of $5640,what is the value of 怎么也看不懂这个函数和一些符号啊～
any 2 point determine a line.if there are 6 point in a plain ,no 3 of which lie on the same line.how many lines are determined by pairs of these 6 point?
on a square gameboard that is diveded into n rows of n squares each.k of these squares lie along the boudary of the gameboard.which of the following is a possible value for
A 10
B 25
C 34
D 42
E 52
3道题比较多,有会的牛人帮下忙哈,实在是解不出来～

提问时间：2020-11-10

答案

第一题.C(x)是一个含有x的方程,x是制造的数量,通过方程,每个固定的x数 会给我们一个固定的c(x)——方程的解&只在x个产品的话费.现在题目告诉了你,要制造20葛产品 需要话费5640元.所以用5640代替c(x),20代替x.就可以求出k是多少.（你等式打错了,看不懂..你就自己求吧）
第二题.同一平面上有六个点,同一条直线上只会有期中的两个点,所以答案是15.
第三题.切割一个正方形,横向的正方形数跟纵向的是一样的.所以外围的正方形数一定要是4的倍数.答案是E
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