A family creates a budget to begin saving for a vacation. The amount the family has can be modeled by the function f ( w ) = 310 + 640 w , where w is the number of weeks since the family started saving. The function g ( w ) = 560 + 382 w describes the family's weekly expenses. Which function, S ( w ) , represents the family's total savings after paying the weekly expenses? S ( w ) = − 250 + 258 w S ( w ) = − − 250 + 258 w S ( w ) = − 250 + 1 , 022 w S ( w ) = − − 250 + 1 , 022 w S ( w ) = 870 + 258 w S ( w ) = 870 + 258 w S ( w ) = 870 + 1 , 022 w