SOLUTION: Given the function y=6x-20/x find the value of f^-1(19)?

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Question 1050234: Given the function y=6x-20/x find the value of f^-1(19)?
Answer by Tatiana_Stebko(1539) About Me  (Show Source):
You can put this solution on YOUR website!
6x-20%2Fx=19
%286x%5E2-20-19x%29%2Fx=0
6x%5E2-19x-20=0
x=%2819%2B-sqrt%28%28-19%29%5E2-4%2A6%2A%28-20%29%29%29%2F%282%2A6%29
x%5B1%5D=%2819-sqrt%28841%29%29%2F12=%2819-29%29%2F12=-5%2F6
x%5B2%5D=%2819%2Bsqrt%28841%29%29%2F12=%2819%2B29%29%2F12=4
Answer: f^-1(19)=-5%2F6, f^-1(19)=4