Direction: Please solve this step-by-step with explanation

39. Solve for u: u^2 + u 6 = 0.

40. Find all x-intercepts and y-intercepts of the graph of the function f(x) = 2x^3 2x^2 84x.

41. Compute the value of the discriminant and give the number of real solutions of the quadratic equation 3x^2 6x + 2 = 0.

45. Solve the equation (y 1)2 = 2y 2 12y + 22 for y.

48. A ball is thrown upward with an initial height of 3 feet with a initial upward velocity 37 ft/s. The ball's height (in feet) after t seconds is given by h = 3 + 37t 16t^2 . Find all values of t for which the ball's height is 23 feet. Round your answer(s) to the nearest hundredth.

49. Find the x-intercept(s) and the coordinates of the vertex for the parabola y = x^2 2x 35.