(sqrt = square root) Express the following in the form a + bi, where a and b are real numbers: sqrt i
sqrt 21+20i
sqrt -15+8i

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?

How many solutions does the nonlinear system of equations graphed bellow have?

The rectangle shown has a perimeter of 108 cm and the given area. its length is 6 more than five times its width. write and solve a system of equations to find the dimensions of the rectangle.