The coffee shop owner explains that she will ork 12 hrs more than you do if you get the job. she will work 50 hrs a week. what equation describes the situation and explain what the variable represents

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