Use pictures or words to explain how you would use the sum of 13 to show how to add in any order

For f(x)=2x+1 and g(x)= x^2 -7, find (f•g)(x)

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

Write the point-slope form of the line passing through (2, -12) and parallel to y=3x.