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Hi all,
I don't understand a specific explanation to this question. Thank you for your help in advance.
Q: If 0 < x < 7 and y < 9, then the lowest possible value for xy is
A. between 60 and 70
B. between 0 and 60
c. 0
d.between 0 and -70
e. less than -70
I understand why the answer is E, but I dont understand why the explanation said: since the lowest value of x is 0, the lowest possible value of xy is also 0. I thought the lowest value of X is 1 as the sign is not equal or greater but just greater.
FYI: This is the whole explanation:" It is helpful to consider extreme values when solving inequality problems, especially when given multiple inequalities. For example, the greatest xy is the product of the highest possible value of x and the highest possible value of y. Since the greatest value of x is less than 7 and the greatest possible value of y is 9, the greatest possible product would be less than 63.
In this situation, we are searching for the lowest possible value of xy. Do not make the mistake of assuming that, since the lowest value of x is 0, the lowest possible value of xy is also 0. Because there is no lower limit to the value of y, there is no lower limit to the value of xy. For example, x could be 2 and y could be -100, and xy could therefore be -200.Alternatively, note that x is a positive number while y could be infinitely negative. Since the product of a positive number and a negative number is negative, xy could be infinitely negative.The correct answer is E.
I don't understand a specific explanation to this question. Thank you for your help in advance.
Q: If 0 < x < 7 and y < 9, then the lowest possible value for xy is
A. between 60 and 70
B. between 0 and 60
c. 0
d.between 0 and -70
e. less than -70
I understand why the answer is E, but I dont understand why the explanation said: since the lowest value of x is 0, the lowest possible value of xy is also 0. I thought the lowest value of X is 1 as the sign is not equal or greater but just greater.
FYI: This is the whole explanation:" It is helpful to consider extreme values when solving inequality problems, especially when given multiple inequalities. For example, the greatest xy is the product of the highest possible value of x and the highest possible value of y. Since the greatest value of x is less than 7 and the greatest possible value of y is 9, the greatest possible product would be less than 63.
In this situation, we are searching for the lowest possible value of xy. Do not make the mistake of assuming that, since the lowest value of x is 0, the lowest possible value of xy is also 0. Because there is no lower limit to the value of y, there is no lower limit to the value of xy. For example, x could be 2 and y could be -100, and xy could therefore be -200.Alternatively, note that x is a positive number while y could be infinitely negative. Since the product of a positive number and a negative number is negative, xy could be infinitely negative.The correct answer is E.
