SOLUTION: when 11 times a certain integer is subtracted from twice the square of the integer, the result is 21 what is the integer

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Question 1175045: when 11 times a certain integer is subtracted from twice the square of the integer, the result is 21 what is the integer
Answer by ikleyn(52898) About Me  (Show Source):
You can put this solution on YOUR website!
.

Let x be the number.


Then from the condition, you have this equation


    2x^2 - 11x = 21.


Solve this quadratic equation using the quadratic formula.


ANSWER.  There are two roots  x= 7  and  x= -3%2F2;  of them,  x= 7 is the only integer solution.

Solved.