Steven wants to buy a couch that costs $475. He has already saved $120. He plans to save $25 a week. Write a function representing Steven's savings after ( x ) weeks.
a) ( f(x) = 475x - (120 + 25x) )
b) ( f(x) = 475 - (120 + 25x) )
c) ( f(x) = 475 - (120 - 25x) )
d) ( f(x) = 475x - (120 - 25x) )