Please help i will mark brainliest

What is the value of 1/3x + 7x when x = 5

The production line where you work can assemble 5 appliers every 30 minutes at this rate how long should it take the line to assemble 125 amplifiers

The number if marbles of different colors stored in a hat is listed below: 4 red marbles 10 green marbles 7 blue marbles. without looking in the hat, dan takes out a marble at random. he replaces the marble and then takes out another marble from the hat. what is the probability that dan takes out a blue marble in both draws?