Question 659764: If 5 times a integer is subtracted from twice the square of the integer, the result is 63. Find the integer
Answer by ReadingBoosters(3246)   (Show Source):
You can put this solution on YOUR website! x = integer
2x^2-5x=63
2x^2 - 5x - 63 = 0
( + )( - ) Mixed sign as the - 63
multiples of 63: 3,21; 7,9; 63,1
Thinking 2 times one of these multiples, minus the other member of the pair needs to give 5, I use 7,9.
Where 2x7=14-9=5
Since the 5 is negative, apply the minus to the 7.
(2x + 9)(x - 7)
x - 7 = 0
x=7 OK
2x+9=0
2x=-9
x=-9/2 NO
The integer is 7
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