Evaluate 3t(t+2)−3t2 for t=19.

To evaluate the expression 3t(t+2) - 3t^2 for t=19, we substitute t with 19 in the expression.

3(19)(19+2) - 3(19)^2

3(19)(21) - 3(361)

(3)(399) - 1083

1197 - 1083

= 114.