What’s the slope of the line

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?

X+y=-4 x-y=2 use elimination with adding and subtraction

How can you find the magnitude of a vector, v = < x, y > , where the horizontal change is x and the vertical change is y?