An electric utility company estimates that the cost, (), of producing kilowatts of electricity is given by () = + , where represents the fixed costs and represents the variable unit costs.

I’m not to sure abt this...

Ifound this on google “that means that the graph of a function with direct variation has these features: it is a straight line: because the slope is the ratio y/x = k. it passes through the origin (0,0): because y = kx = k (0) = 0.” i hope this you for what your looking for