11. If x and y are integers and xy+x^2 is oddh which of the following statements must be true?① x is odd② y is odd③ x+y is oddA. ①B. ③C. ① and ②D. ① and ③E. ② and ③2. For how many integers n is (2n+1)(3n-1) a negative number?A. NoneB. OneC. ...
If x and y are integers such that x3 = y2, which of the following could not be the value of y (A) -1(B) 1(C) 8(D) 16(E) 27 相关知识点: 试题来源: 解析 D Test each choice until you find the correct answer. Could y = -1 Is there an integer x such that x3 = (-1)...
因为任意两个数x、y，从x到y一共有x-y+1个数。而题目问的是这两个数之间有几个数（不包括这两个数）所以这两个数之间自然就是有x-y+1-2=x-y-1个数了 方便理解的话，可以把x和y用具体数字带入 比如x=3，y=1 从x到y一共有3个数，两个数之间有1个数 ...
GRE数学题 If x and y are integers and x>y>0If x and y are integers and x>y>0,how many integers are there between ,but not including,x and x-y-1 答案 题目:xy是整数,并且x>y>0,有多少个不包括xy在内的整数在xy之间.我觉得用直接代数求就行,比如x是5,y是2,然后选符合的那个选项...
解析 A [解析] 因为x和y都是整数,所以由x2<y可以推出一定有x<y,从而充分地回答了x不大于y,所以(1)充分(注:对题目中的问题否定的回答也是充分的回答);通过举例可以验证(2)不充分,如对于满足[*]的x=1,y=2有x<y,而对于满足[*]的x=4,y=3,则有x>y。
B [解析] 根据题意可知X△Y中的整数数目为: (10-6)+(18-6)=16。 相关推荐 1If X and Y are sets of integers, X△Y denotes the set of integers that belong to set X or set Y, but not both. If X consists of 10 integers, Y consists of 18 integers,and 6 of the integers are in...
[解析] 因为xy+1能否被3整除,不但取决于x的值,而且还取决于y的值,所以(1)和(2)单独都很明显不充分;根据(1)+(2)可得: x=3m+1,y=9n+8,其中m,n是整数。 把这两个式子代入xy+1可得: xy+1=(3m+1)(9n+8)+1 =27mn+24m+9n+84-1 =3(9mn4-8m+3n+3) 因此xy+1能被3整除,所以(1)...
If x and y are integers whose least common multiple is a perfect square and whose greatest common divisor is a prime number,which could represent the ordered pair (x,y)?The answer is (18,4) ; but I just dont know why (9,1) couldn't be the right answer,I figure it is right,too...
If R2={(x,y)∣xandy are integers and x2+y2=64} is a relation. Then find R2. ভিডিও সমাধান | ShareSave উত্তর Step by step video solution for If R_2={(x,y)| x and y are integers and x^2 +y^2=64} is a relation. Then find ...
[解析] (1)不充分,因为满足y不等于1,且x是y的倍数的y有无穷多个,此时y既可以等于2,也可以不等于2;根据(2)可设x 2=ny,由x是y的倍数可设x=my,其中m和n都是正整数,把这两个式子相减可得(n-m)y=2,因为n-m和y都是正整数,所以当n-m取1时,y取2,当n-m取2时,y取1,因此(2)也不充分;根据以...