更多"If x and y are integers such that x"的相关试题:
[单项选择]多项式3x4-2x3y-8x2y2分解因式得（）。
A. x2(3x-8y)
B. (x+2y)(3x-4y)
C. (x-2y)(3x+4y)
D. x2(x-2)(3x+4)
E. x2(x-2y)(3x+4y)
[单项选择]设有函数z=x3+y2与z=(x2+y2)2，易知有驻点(0，0)，则在该点处
A. 函数z=x3+y2有极小值，而函数z=(x2+y2)2无极值．
B. 函数z=x3+y2无极值，而函数z=(x2+y2)2有极小值．
C. 上述两个函数都有极值．
D. 上述两个函数都无极值．
[单项选择]假设某项网络工程项目由设备x1、x2、x3、x4、x5和设备y1、y2串联组成。其中，设备x1必须在左端或右端，且设备y1、y2必须相邻，则共有（）种排法。
A. 120
B. 192
C. 360
D. 480
[单项选择]If r and s are integers and rs+r is odd, which of the following must be even
A. r
B. s
C. r+s
D. rs-r
E. (E) r2+s
[单项选择]The product of three consecutive integers must be
Ⅰ. Divisible by 3
Ⅱ. Divisible by 5
Ⅲ. Divisible by 6
A. Ⅰ only
B. Ⅱ only
C. Ⅰand Ⅱ only
D. Ⅰ and Ⅲ only
E. (E) Ⅰ, Ⅱ, and Ⅲ
[单项选择]The sum of four consecutive odd positive integers is always
A. an odd number
B. divisible by 4
C. a prime number
D. a multiple of 3
E. (E) greater than 24
[单项选择]How many integers between 100 and 150, inclusive, can be evenly divided by neither 3 nor 5 ？（）
A. 33
B. 28
C. 27
D. 25
E. 24
[单项选择]How many integers 72 greater than 10 and less than 100 are there such that, if the digits of n are reversed, the resulting integer is n+9 ？（）
A. 5
B. 6
C. 7
D. 8
E. 9
[单项选择]If a sequence of 8 consecutive odd integers with increasing values has 9 as its 7th term, what is the sum of the terms of the sequence ？（）
A. 22
B. 32
C. 36
D. 40
E. 44
[单项选择]If M and N are positive integers that have remainders of 1 and 3, respectively, when divided by 6, which of the following could NOT be a possible value of M+N ？（）
A. 86
B. 52
C. 34
D. 28
E. 10
[单项选择]Set S consists of n distinct positive integers, none of which is greater than 12. What is the greatest possible value of n if no two integers in S have a common factor greater than 1 ？（）
A. 4
B. 5
C. 6
D. 7
E. 11
[单项选择]
How many positive integers k are there such that 100k is a factor of (22)(3)(53) ？（）
A. None
B. One
C. TWO
D. Three
E. Four
[单项选择]How many of the integers between 25 and 45 are even ？（）
A. 21
B. 20
C. 11
D. 10
E. 9
[单项选择]For how many integers n is 2n=n2
A. None
B. One
C. Two
D. Three
E. (E) More than three
[单项选择]How many positive 4-digit integers begin (on the left) with an odd digit and end with an even digit
A. 250
B. 500
C. 2,000
D. 2,500
E. 5,000
[单项选择]In writing all of the integers from 1 to 300, how many times is the digit 1 used
A. 60
B. 120
C. 150
D. 160
E. 180
[单项选择]If x and y are positive integers and x is a multiple of y，is y=2 ？（）
(1)y≠1
(2)x+2 is a multiple of y.
A. 条件(1)充分，但条件(2)不充分．
B. 条件(2)充分，但条件(1)不充分．
C. 条件(1)和(2)单独都不充分，但条件(1)和条件(2)联合起来充分．
D. 条件(1)充分，条件(2)也充分．
E. 条件(1)和条件(2)单独都不充分，条件(1)和条件(2)联合起来也不充分．
[单项选择]If the two-digit integers M and N are positive and have the same digits, but in reverse order, which of the following CANNOT be the sum of M and N ？（）
A. 181
B. 165
C. 121
D. 99
E. 44
