If N is the midpoint of PR and PN=4x+5 and NR=7x-16, find the length of PR

14x-11

the length of PR = the length of PN + the length of NR

the length of PR = 4x + 5 + 7x - 16

the length of PR = 4x + 7x + 5 - 16

the length of PR = 11x - 11