I need help with the questions in the pdf file. Thank you.

What is the name used to describe a graph where for some value of x, there exists 2 or more different values of y?

Find the volume of the described solid.the solid lies between planes perpendicular to the x-axis at x = 0 and x=7. the cross sectionsperpendicular to the x-axis between these planes are squares whose bases run from the parabolay=-31x to the parabola y = 30/x.a) 441b) 147c) 864d) 882

Two numbers have a sum of -19. one number is x. what expression represents the other number?