Let's use the variable r to represent the number of runners on last year's team and x to represent the number of runners this year.
Since the number of runners this year is 6 more than 4 times the number of runners on last year's team, we can write the following equation:

Also, half the number of runners this year are females, so the expression for the number of females this year is:

Therefore the answer is yes, the expression for the number of females is (4r+6)/2.