f(x)=6x+2f(x)=6x+2 , find f(x+3)f(x+3).
Select one:
a. f(x+3)=6x2+20x+6f(x+3)=6x2+20x+6
b. f(x+3)=6x+5f(x+3)=6x+5
c. f(x+3)=6x+20f(x+3)=6x+20
d. f(x+3)=x+5