[讨论]请教两个gmatprep里的数学题

creditadvices

Before being simplified, the instructions for computing income tax in

Country R were to add 2 percent of one's annual income to the average

(arithmetic mean) of 100 units of Country R's currency and 1 percent

of one's annual income. Which of the following represents the

simplified formula for computing the income tax, in Country R's

currency, for a person in that country whose annual income is I?

A) 50+I/200
B) 50+3I/100
C) 50+I/40
D) 100+I/50
E) 100+3I/100

If xy=1, what is the value of 2(x+y)^2/2(x-y)^2

答案是16，我总觉得题目错了，请教各位NN

qiancheng

第二题讨论过了，题目错了

第一题：

理解了那一句话后把式子写出来简化就行了：……add……to the average of……and……,

那么，根据题意tax就是2％I＋（100＋1％I）/2，

简化后不就是c的答案嘛：）