Ajar contained 18 red marbles, 14 green marbles, and 20 blue marbles. a marble was selected at random, the color was recorded, and the marble was placed back in the jar. the table shows the results after 60 trial. what was the relative frequency of selecting a blue marble? enter your answer in the box to the nearest percent.

The function a represents the cost of manufacturing product a, in hundreds of dollars, and the function b represents the cost of manufacturing product b, in hundreds of dollars. a(t) = 5t + 2 b(t) = 7t - 2t +4 find the expression that describes the total cost of manufacturing both products, a(t) + b(t). a. 7t^2 - 7t + 2 b. 7t^2 + 3 +6 c. 7t^2 + 7t - 6 d. 7t^2 - 3t + 6