Find the Sales Necessary to Break Even (R - C $C = 6.7 \sqrt { x } + 3000 , R = 8.1 x$

Multiple Choice

Find the sales necessary to break even (R - C = 0) for the cost C of producing x units and the revenue R obtained by selling x units.(Round to the nearest whole unit.) $C = 6.7 \sqrt { x } + 3000 , R = 8.1 x$

A) No real solution
B) 387 units
C) 355 units
D) 377 units
E) 355 units or 387 units