菜鳥小妹求思路~~~~~~~~~~~~~~~

hijenny

173.18259-!-item-!-187;#058&011463

In a certain state, gasoline stations compute the price per gallon p, in dollars, charged at the pump by adding a 4 percent sales tax to the dealer's price per gallon d, in dollars, and then adding a gasoline tax of $0.18 per gallon.Which of the following gives the dealer's price per gallon d in terms of the price per gallon p charged at the pump?



(A) d = p - 0.22

(B) d = P/ 1.22

(C) d = (P/1.04) – 0.18

(D) d = (P - 0.18)/1.04

(E) d = (P-0.04)/1.18


選D

177.When a certain tree was first planted, it was 4 feet tall, and the height of the tree increased by a constant amount each year for the next 6 years.At the end of the 6th year, the tree was 1/5 taller than it was at the end of the 4th year.By how many feet did the height of the tree increase each year?



(A)3/10

(B)2/5

(C)1/2

(D)2/3

(E)6/5


選D

179.19312-!-item-!-187;#058&012220

If two sides of a triangle have lengths 2 and 5, which of the following could be the perimeter of the triangle?

I.9

II.15

III.19



(A) None

(B) I only

(C) II only

(D) II and III only

(E) I, II, and III

選A
我覺得三個都是 = =

hijenny

懇請賜教

catherine9119

179 题 你要根据两边和大于第三边来求。。
告诉你周长 你能算出第三边的长度，
像(1) 三边长分别为2,2,5  所以不存在。。

Nickyl86

1. 根据题意，得出p= 1.04d+0.18，然后化一化就能得到D这个答案了，不知道你是不是题目没看懂，意思是，这个price P，是d加了0.04的tax外加0.18块固定费用
2. 注意是“1/5 taller than it was at the end of the 4th year”，则4+6x=1.2(4+4x)，x=2/3
3. 第三边的范围是（3，7）则，周长范围（10，14），三个都不符合