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When 8 is subtracted from the square of a number, the result is 7times the number. Find the positive solution

User ProEvilz
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1 Answer

10 votes
10 votes

Answer:

x=8 , x=-1

Explanation:

let the number is x

According to the condition


{x}^(2) - 8 = 7x \\ {x}^(2) - 7x - 8 = 0 \\ {x}^(2) - 8x + x - 8 = 0 \\ x(x - 8) + 1(x - 8) = 0 \\ (x - 8)(x + 1) = 0 \\ x - 8 = 0 \: or \: x + 1 = 0 \\ x = 8 \: or x = - 1

User Mark Vayngrib
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