Two Data Sufficient

lisaislisa

[em18][em08][em18][em08][em18][em08][em18][em08]

If both X&Y are nonzero integers , what is Y/X ?
1)X=6
2)Y^2/X^2=1

the An is E but MINE is (B)
since Y^2/X^2=1 then Y/X = +-1 as Yand X , obviously two different numbers so Y/X can not be 1 then it is -1

so do I misunderstand ? X and Y sign for different numbers ?
[em06][em27][em06][em27][em06][em27]

lisaislisa

another problem goes like this ...

In rectangular coordinate system , is (r,s) and (u,v) equidistant from the origin ?
1)r+s=1
2)u=1-r and r=1-s

the An is C but MINE is (E)
from the both of the two prerequisites we get r+s=1 and u+v=1 means (r,s) and (u,v) are both in the line x+y=1
but to get the result ,r^2 +s^2=u^2+v^2 is required , isn't it ?

THANK U ^^

tongxun

你的两个答案都是对的。B、E。

daydream

In rectangular coordinate system , is (r,s) and (u,v) equidistant from the origin ?
1)r+s=1
2)u=1-r and v=1-s

the An is C but MINE is (E)
--------------------------------
由(2): u^2+v^2=(1-r)^2+(1-s)^2 = r^2+s^2-2(r+s)+2
由(1): r+s=1 ==> u^2+v^2= r^2+s^2
所以答案为: C

bill_cheung

the first one
it is never mentioned that X and Y represent different figures.
so the answer still should be E.

kanecao

THE FIRST ONE:

If both X&Y are nonzero integers , what is Y/X ?
1)X=6; 2)Y^2/X^2=1

由2）得y/x=1,or y/x=-1，故不能确定！

lisaislisa

thank you daydream ^^ it's an interesting problem !
and about my first question
when there are different letters , it doesn't mean 'different' numbers ?
there is a rule , right ?


good luck to all ^^

陈月麟

lisalisa,

The second question. I think we cannot answer this question because we do not know where the origin is.
请问我的思路有错吗？
谢谢！

lisaislisa

to LinLin :
we don't know where it origin is ? I am a bit confussing .
I suppose origin means the point (0,0) , isn't it ...

from LIsa ^^