Could someone me with this problem, . it’s algebra.

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?

Solve the triangle. a = 21°, c = 105°, c = 5

Select all of the following expressions that are equal to 2.5.