How many ways can 7 paintings be lined up in a wall

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

Find an equation of the line perpendicular to the graph of 28x-7y=9 that passes through the point at (4,1)

James was playing a game with his friends. he won 35 points. then he lost 15, lost 40 and won 55. how did he come out