Senior Manager
Joined: 23 Oct 2015
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Location: United States (NH)
Concentration: Leadership, Technology
WE:Information Technology (Non-Profit and Government)
Re: Properties of number
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02 Sep 2021, 20:53
๐ and ๐ are two integers such thatโ5(๐^2+๐) is a positive number. Determine whether each of the following expression is positive, negative, 0, or โNo unique answerโ.
a)๐ - negative
b)๐+๐ - negative
c)โ๐ - positive
d)๐โ๐ - positive (INCORRECT: Must be No unique answer)
x could be negative. Note, square of a negative number is always positive.Also, it could be a very very large number, "negatively". and could make x-y a negative value. Since both positive and negative values are possible, the choice would be "No unique answer".
e)(๐^2+๐)/๐ - positive
[color=#ff0000]f)๐^2 - no unique answer (INCORRECT: Must be positive)
Irrespective of whether x is positive or negative integer, x^2 is always a positive integer.
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g)๐^2+๐^2 - positive