Answer:
39+5d
Step-by-step explanation:
distribute 5 to (9+d)
then you will have 45+5d-6
then combine like terms and you get 39+5d
0.8 i guess
circumference is 81.68
area is 530.93
C=2πr=2·π·13≈81.68141
A=πr2=π·132≈530.92916