When you are completing pythagorean theorum are you solving for the area?

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

Which of the following is the result of expanding the series

Is it greater than or less than7*3_9*2