Answer :

Substitute 12 in for x

f(12) = (3/4)12 + 5/6

f(12) = (0.75 x 12) + 0.83

f(12) = 9 + 0.83

f(12) = 9.83
f(12)=([tex] \frac{3}{4} [/tex] x 12) + 5/6
       = 9+[tex] \frac{5}{6} [/tex]
       =9[tex] \frac{5}{6} [/tex]
       =59/6