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02-05-2019
Mathematics

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The square of a number decreased by 4 times the number equals 21. Find the number.

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sprinkles1222 sprinkles1222

02-05-2019

Answer: 7

Explanation:

x^2-4x=21

x^2-4x-21=0

(x+3)(x-7)=0

x=-3

x=7

*** if you need to find the positive # only, the ANSWER is 7****

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