If f(a)=3a+6, what is the value of (f(2a)+f(a)) ?
Choose the most appropriate option
A) 2a-4
B) 8a-7
C) 9a+5
D) 8a+12
E) 3a+5
f(a)=3a+6   f(2a)= 5a+6   (f(2a)+f(a)) = 5a+6+3a+6 = 8a+12   Answer is 8a+12
<result>D</result>
If f(a)=3a+6, what is the value of (f(2a)+f(a)) ?