Ben currently has $70 in his trip fund. he makes $45 per week doing yard work for his neighbors. he keeps $18 of the $45 for weekly expenses. the remaining amount goes into his trip fund. which function can be used to determine the amount of money (y), in dollars, that ben has in his trip fund at the end of x weeks? a y=70+27x b y=52+45x c y=45+52x d y=27+70x