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～