f(a + 2)= 3a + [tex]\frac{17}{2}[/tex]
substitute x = a + 2 into f(x)
f(a + 2) = 3(a + 2) +[tex]\frac{5}{2}[/tex]
= 3a + 6 + [tex]\frac{5}{2}[/tex] = 3a + [tex]\frac{17}{2}[/tex]
