[数学讨论稿1] 4.2数学讨论稿1-100（更新至：100 - 4/15 17:18）

joyjoe97

爱你····楼主····

tanghanrui

设x=10m+1, x=3n+2，x=30k+?,求？
10m+1=3n+2, 10m=3(n-3)+10
令n-3=10k,则m=3k+1
代入得x=10(3k+1)+1=30k+11

海绵小宝

噢噢，原谅我的粗心

海绵小宝

十二题大家表纠结了，等题目有完整版的，会再确认的

海绵小宝

马上会更新一下。说明together not sufficient

LinsenSun

小生又飘过····

敏儿猫猫

亲，如果小圆在大园的一侧怎么保证它们之间的圆心距都是5呢？

潇遥枫

第7题
ax>ay --> i) a>0, x>y>0 ii) a<0, x<y<0
同理 bx>by --> i) b>0, x>y>0 ii) b<0, x<y<0
若x>y>0，则 a>0, b>0 --> abx>aby
若 x<y<0， 则 a<0, b<0 ---> ab>0 --> abx<aby
所以应该选E

Nancy遗

LZ
第21题是考古GWD第22套的

Q32:

    Number Studying    Number Not    Total
    Biology    Studying Biology    
Number              18
of Boys              
Number              
of Girls              
Total    26         

The table above shows the number of students in a certain high school class who are boys and the number of students in the class who are studying biology.  What is the total number of students in the class?
(1)      Of the boys in the class, 15 are studying biology.
(2)    The number of girls in the class is twice the number of students in the class who are not studying biology.
    
A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
C. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
D. EACH statement ALONE is sufficient.
E. Statements (1) and (2) TOGETHER are NOT sufficient.
答案选D~~~

ubccoming

LZ
第21题是考古GWD第22套的

Q32:

    Number Studying    Number Not    Total
    Biology    Studying Biology    
Number              18
of Boys              
Number              
of Girls              
Total    26          

The table above shows the number of students in a certain high school class who are boys and the number of students in the class who are studying biology.  What is the total number of students in the class?
(1)      Of the boys in the class, 15 are studying biology.
(2)    The number of girls in the class is twice the number of students in the class who are not studying biology.

A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
C. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
D. EACH statement ALONE is sufficient.
E. Statements (1) and (2) TOGETHER are NOT sufficient.
答案选D~~~

-- by 会员 Nancy遗 (2012/4/5 20:43:42)

B吧~~~