Joel and Kevin are each putting money in a savings account to buy a new bicycle. The amount, in dollars, in Joel’s savings account, x weeks after the start of the year, is modeled by function j. The amount of money in Kevin’s account, at the same time, is modeled by function k. j(x) = 25 + 3x
k(x) = 15 + 2x

Which function correctly represents how much more money, in dollars, is in Joel’s account than in Kevin’s account x weeks after the start of the year?

A.
(j − k)(x) = 40 + 5x
B.
(j − k)(x) = 40 + x
C.
(j − k)(x) = 10 + 5x
D.
(j − k)(x) = 10 + x