Sunland provides environmentally friendly lawn services for homeowners. Its operating costs are as follows.

$\backslash$table$[[$Depreciation$,$$$1,400,$per month$],[$Advertising$,$$$300,$per month$],[$Insurance$,$$$4,930,$per month$],[$Weed and feed materials,$$21,$per lawn$],[$Direct labor,$$11,$per lawn$],[$Fuel$,$$$2,$per lawn$]]$

Sunland charges $$85$ per treatment for the average single$-$family lawn.

$($a$)$

Determine the company's break$-$even point in number of lawns serviced per month.

Break$-$even point

lawns