E is between D and F. Find DF. PLEASE HELP, PICTURE PROVIDED— DUE TMMR

Answer:
24
Step by-step explanation:
6x=3x-1+13
common like terms (-1+13)
6x=3x+12
subtract 3x on both sides
3x=12
divide 3x on both sides
x=4
insert 4 into equation 6*4=24
3(4)-1+13=24