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The square of what number is 6 greater than 5 times the number

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timw996 | Student, Grade 10 | Salutatorian

Posted September 16, 2013 at 2:51 PM via web

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The square of what number is 6 greater than 5 times the number

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justaguide | College Teacher | (Level 2) Distinguished Educator

Posted September 16, 2013 at 2:53 PM (Answer #1)

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The square of a number is 6 greater than 5 times the number. Let the number be denoted by X.

X^2 = 6 + 5X

=> X^2 - 5X - 6 = 0

=> X^2 - 6X + X - 6 = 0

=> X(X - 6) + 1(X - 6) = 0

=> (X + 1)(X - 6) = 0

=> X = -1 and X = 6

The square of the numbers -1 and 6 is 6 greater than 5 times the number.

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atyourservice | Student, Grade 10 | Valedictorian

Posted July 29, 2014 at 11:01 AM (Answer #2)

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The square of what number is 6 greater than 5 times the number

x^2 = 6 + 5x
now move the problems to the same side:
 
x^2 - 5x - 6 = 0
 
multiply a by c and find the factors, and add it to b
 
 X^2 - 6X + X - 6 = 0
 
group
 
 (X^2 - 6X) +( X - 6) 
 
factor:
 
x (x - 6) + 1 ( x - 6)
 
(x + 1) (x - 6)
 
x = -1   x = 6
 
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givingiswinning | Student, Grade 10 | Valedictorian

Posted August 15, 2014 at 11:18 PM (Answer #3)

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x^2 = 6 + 5x
x^2 - 5x - 6 = 0
 
multiply a by c and find the factors, and add up to b
 
 X^2 - 6X + X - 6 = 0
 
group
 
 (X^2 - 6X) +( X - 6) 
 
factor
 
x (x - 6) + 1 ( x - 6)
 
(x + 1) (x - 6)
 
set equal to 0:
x + 1 =0
 
x = -1  
 
x - 6 = 0
 
x = 6

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