The answer is a+6b, if you want to know the proof please comment on this post
Evaluate them
A.
f(5), x>1 so square it, f(5)=25
A is wrong
B.f(2), x>1 so square it, f(5)=4
B is correct
C. f(1), x=1 so the result is 5, f(1)=5
C is correct
D. f(-2), x<1 so double it, f(-2)=-4
D is wrong
answers are B and C