Step-by-step explanation:
f(x)=-3x+4
f(a)= -3a +4
So,
2f(a)= f(a) + f(a)
=(-3a +4) +(-3a + 4)
=-3a + 4 -3a - 4
=-6a
f(2a)=2(-3a + 4)
=-6a +8
f(a+2)=(-3a + 4) + 2
= -3a +4 +2
= -3a + 6
f(a) + f(2)= -3a +1+5
because, f(2)= -3(2)+1
=-6+1
=5
and f(a)= -3a+1
