后天考试,求助几个数学题~~~~~~~~~~~~~~~~~~

zhuang2081

首先请问下椭圆   双曲线  之类的需要看吗,我做题从来没遇到过.....................................................

1    which of the following lists the number of points at which a circle can intersect a triangle?(我就纯粹不理解这道题要干嘛呢)
A  2 6
B  2  4    6  
C   1   2   3    4
D   1   2   3   4     6
E    1    2   3   4   5    6                            the anwser is   e

2    at a certain bakery, each roll costs r cents and each doughnut costs d cents,   if    alfredo bought rolls and doughtnuts at the bakery,how many cents did he pay for each roll?

(1)  he paid  5  for 8rolls and 6 doughtnuts
(2) he would have paid  10   if he had bought  16rolls  and  12 doughtnut              the anwser is   e


3        at a certain supplier, a machine of type A costs 20000 and a machine of type B costs 50000, each machine can be purchased by making a 20 percent down payment and repaying the remainder of the cost and the finance charges over a period of time ,   if the finance charges are equal to 40 percert of the remainder of the cost, how much less would 2 machines of type A cost than 1 machine of type B under this arrangement

the anwser is 13200

sdcar2010

1    which of the following lists the number of points at which a circle can intersect a triangle?(我就纯粹不理解这道题要干嘛呢)
A  2 6
B  2  4    6  
C   1   2   3    4
D   1   2   3   4     6
E    1    2   3   4   5    6  

This question asks you to think about all the possibilities that a triangle can interact with a circle.  Even answer E missed one option: zero!

sdcar2010

2    at a certain bakery, each roll costs r cents and each doughnut costs d cents,   if    alfredo bought rolls and doughtnuts at the bakery,how many cents did he pay for each roll?

(1)  he paid  5  for 8rolls and 6 doughtnuts
(2) he would have paid  10   if he had bought  16rolls  and  12 doughtnut

This is a simple algebra.  You'd better list the equations for 1) and 2) then compare them.

sdcar2010

3        at a certain supplier, a machine of type A costs 20000 and a machine of type B costs 50000, each machine can be purchased by making a 20 percent down payment and repaying the remainder of the cost and the finance charges over a period of time ,   if the finance charges are equal to 40 percert of the remainder of the cost, how much less would 2 machines of type A cost than 1 machine of type B under this arrangement

This question asks you to calculate the financial charge for each machine and compare the difference thereof.  Use your brain and pencil to come up with a number!

zflucy11

1.是问一个圆和一个三角形的交点个数可能有几个，这几个数都没问题，画一下就知道了~
2.两个条件列出来的式子一样，所以不充分
3.你可能题目没看懂，是说直接付掉20%，剩下的80%延期付，但有融资成本（延期付款部分的40%），问这样计算1台B设备的开支比2台A设备多多少，不难的