Answer:
r=9
EF = 55
Step-by-step explanation:
CF = ED
9r - 6 = 8r+3
Subtract 8r from each side
9r-8r - 6 = 8r-8r+3
r-6 =3
Add 6 to each side
r-6+6 = 3+6
r = 9
EF= CD = 4r+19
= 4*9+19
=36+ 19
=55
