Diberikan f(x) =2xpangkat2+x+6, dapatkan f(3t+1)

f (x) = 2x^2 + x + 6
f ( 3 t +1) = 2(3t+1)^2 + (3t+1) +6
= 2 ( 9t^2 + 6t +1 ) +3t +1 +6
= 18t^2 +12t +2 +3t +1 +6
= 18t^2 +15t + 9