Are these ratios equivalent? 18 : 45 and 2 : 6

Which is the equation of a line perpendicular to the line with the equation 3x+4y=8

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?

If f(x)= sqrt4x+9+2, which inequality can be used to find the domain of f(x)?