I need help with these questions for Working with Standard and Vertex Forms of the Quadratic Function, the first image is the instructions for the questions and the rest of the images have been labelled and put in order of the questions:

When the solutions to each of the two equations below are graphed in the xy-coordinate plane, the graphs of the solutions intersect at two places. write the y-cordninates of the points of intersection in the boxes below in order from smallest to largest. y=2x y=x^2-3

Acircle has a circumference of 28.36 units what is the diameter of the circle

Anyone know these questions? i need ,.