A small company borrows money and remains in debt to its lenders for a period of time. The function f(x)=-8x^2+8x+50 represents the amount of debt the company has, in thousands of dollars, x years after opening its business.
Approximately how many years after opening its business will the company be out of debt?
3.3 years
3.7 years
3.1 years
3.5 years
