Adding & subtracting fractions

Icould really use some with this question.

The unpaid balance on a mastercard charge was $1,056.23. during the month, payments of $300 and $250 were made and charges of $425 and $274.16 were added. if the finance charge is 1.2% per month on the unpaid balance, find the new balance at the end of the month. $1,205.39 $1,218.06 $918.06 $1,768.06

Ef is a median of trapezoid abcd. the length of ab is 12, and the length of cd is 18. the length of bf is 4. what is the length of fc?