SOLUTION: seven times a number is subtracted from 2 times its reciprcoal. the result is 13 what is the number?

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Question 570706: seven times a number is subtracted from 2 times its reciprcoal. the result is 13 what is the number?
Answer by Maths68(1474) About Me  (Show Source):
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Let x be the number

Given
Seven times of x= 7x
Reciprocal of x = 1%2Fx
2 times of reciprocal of x = 2%2Fx

7x-2%2Fx=13
%287x%5E2-2%29%2Fx=13
7x%5E2-2=13x
7x%5E2-13x-2=0
7x%5E2-14x%2Bx-2=0
7x%28x-2%29%2B1%28x-2%29=0
%287x%2B1%29%28x-2%29=0
7x%2B1=0 or x-2=0
7x=-1 or x=2
7x%2F7=-1%2F7 or x=2
cross%287%29x%2Fcross%287%29=-1%2F7 or x=2
x=-1%2F7 Reject
So
x=2
Number is 2


Check
=====
7%28x%29-x%2F2=13
Put x=2
7%282%29-2%2F2=13
14-2%2F2=13
14-1=13
13=13