PLEASE HELP, ITS SIMPLE WILL GIVE BRAINLIEST

Solve 2x+y=3 x+y=5 in substitution method

Pat listed all the numbers that have 15 as a multiple write the numbers in pats list

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?