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what are the two possible values of x?
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18 Feb 2021, 00:21
18 Feb 2021, 00:21
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If \((x-5)^2=900\) , what are the two possible values of x?
Indicate two such numbers.
A 10
B –10
C –25
D 30
E 35
F 40
Kudos for the right answer and explanation
Question part of the project GRE Quantitative Reasoning Daily Challenge - (2021) EDITION
GRE - Math Book
Indicate two such numbers.
A 10
B –10
C –25
D 30
E 35
F 40
Kudos for the right answer and explanation
Question part of the project GRE Quantitative Reasoning Daily Challenge - (2021) EDITION
GRE - Math Book
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Re: what are the two possible values of x?
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18 Feb 2021, 01:10
18 Feb 2021, 01:10
Carcass wrote:
If \((x-5)^2=900\) , what are the two possible values of x?
Indicate two such numbers.
A 10
B –10
C –25
D 30
E 35
F 40
Indicate two such numbers.
A 10
B –10
C –25
D 30
E 35
F 40
\((x - 5)^2 = 900\)
Square rooting both sides;
\((x - 5) = ±30\)
Either, \((x - 5) = +30\) or \((x - 5) = -30\)
So, \(x = 35\) or \(x = -25\)
Hence, option C and E
Re: what are the two possible values of x?
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18 Feb 2021, 07:53
18 Feb 2021, 07:53
1
Hi,
As all the options either end with a 0 or 5. Thus, x0-5 will have a units digit of 5 and the square of 5 as well.
Hence we need number with units digit 5 to get 0 unit the units digit. Only option C & E satisfies.
IMO C & E
Hope this helps!
As all the options either end with a 0 or 5. Thus, x0-5 will have a units digit of 5 and the square of 5 as well.
Hence we need number with units digit 5 to get 0 unit the units digit. Only option C & E satisfies.
IMO C & E
Hope this helps!
