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For a certain integer x, the units digit of (x+2)^2 is 9. Which of the
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06 Mar 2017, 03:51
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70% (01:55) correct 30% (02:07) wrong based on 795 sessions
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For a certain integer x, the units digit of (x+2)^2 is 9. Which of the following could be the units digit of x+1? A. 0 B. 3 C. 4 D. 5 E. 7
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Re: For a certain integer x, the units digit of (x+2)^2 is 9. Which of the
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07 Mar 2017, 17:48
Bunuel wrote: For a certain integer x, the units digit of (x+2)^2 is 9. Which of the following could be the units digit of x+1?
A. 0 B. 3 C. 4 D. 5 E. 7 The only way to get a units digit of 9 when squaring an integer is for the original integer to have a units digit of 3 or 7. Thus, since (x+2)^2 has a units digit of 9, x could be 1, 5,5, or 9. Let’s plug each value into x + 1. When x = 1, x + 1 = 2, which is not an answer choice. When x = 5, x + 1 = 6, which is not an answer choice. When x = 5, x + 1 = 4 = 4, which IS an answer choice. When x = 9, x + 1 = 8 = 8, which is not an answer choice. Answer: C
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Re: For a certain integer x, the units digit of (x+2)^2 is 9. Which of the
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06 Mar 2017, 09:06
Bunuel wrote: For a certain integer x, the units digit of (x+2)^2 is 9. Which of the following could be the units digit of x+1?
A. 0 B. 3 C. 4 D. 5 E. 7 (x+2)^2 = 9 So, Units digit of (x+2) will be 3 or 7 Thus, the units digit of x can be either 1 or 5 Quote: the units digit of x+1 Units digit of x+1 must be 4 or 6 Among the given option only (C) is possible, hence this is our answer...
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For a certain integer x, the units digit of (x+2)^2 is 9. Which of the
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06 Mar 2017, 06:19
I'll bet my uncle's beercan collection it's C; i.e., x = 5, 15, etc.



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Re: For a certain integer x, the units digit of (x+2)^2 is 9. Which of the
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06 Mar 2017, 09:37
X= 5
5 + 1 = 4 Absolute value = 4
Answer: c



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Re: For a certain integer x, the units digit of (x+2)^2 is 9. Which of the
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06 Mar 2017, 18:53
x could be 5 or 1. If x is one, then we get a result of 4. Therefore the answer is C.



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Re: For a certain integer x, the units digit of (x+2)^2 is 9. Which of the
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08 Mar 2017, 03:39
if the unit digit of square of the number is 9, the unit digit will be either 3 or 7 if x is positive and 5 and 9 if x is negative hence the unit digit of x will be either 1 or 5 if x is positive and 5 and 9 if x is negative hence x+1 will yield the unit digit as 2 or 6 if x is positive and 4 and 8 if x is negative. looking at the option we can see that 4 is the only option Option C
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Re: For a certain integer x, the units digit of (x+2)^2 is 9. Which of the
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18 Mar 2017, 15:05
(x+2)^2=9 it's supposed to end 3 or 7
I tried negative numbers: 5+3=3^2=9 5+1=4



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Re: For a certain integer x, the units digit of (x+2)^2 is 9. Which of the
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15 May 2017, 05:43
A. 0 B. 3 C. 4D. 5 E. 7 Unit digit on squaring any number can be 9 if and only if unit number of which we are squaring, must be either 3 or 7 And to have 7 or 3 at unit digit x can be 1,5,5,9 When x = 1, x + 1 = 2, When x = 5, x + 1 = 6, When x = 5, x + 1 = 4 = 4, When x = 9, x + 1 = 8 = 8,
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Re: For a certain integer x, the units digit of (x+2)^2 is 9. Which of the
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06 Feb 2019, 23:15
Bunuel wrote: For a certain integer x, the units digit of (x+2)^2 is 9. Which of the following could be the units digit of x+1?
A. 0 B. 3 C. 4 D. 5 E. 7 Key word : certain integer x (x+2)^2 is 9 x= 9 or x = 5 or x = 5 or x = 1 Only value which is present after using the above values in x+1 4 C
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Re: For a certain integer x, the units digit of (x+2)^2 is 9. Which of the
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10 Mar 2019, 00:01
(x+2)^2 = 9, means > last digit of x must be 5,(5+2=3) x+1> _/(x+1)^2 or, x+1>therefore last digit 4 (5+1=4)



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Re: For a certain integer x, the units digit of (x+2)^2 is 9. Which of the
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01 May 2019, 09:35
Solution to this problem has already been discussed in detail. Just want to add another slightly different approach to select from the available options Unit digit of (x+2)^2 is 9, so x has to be an odd number and therefore x+1 has to be an even number, which is only one of the available option, i.e. 4
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Re: For a certain integer x, the units digit of (x+2)^2 is 9. Which of the
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