What three consecutive even numbers added up together equal 42

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

Express the following as a function of a single angle. cos(60) cos(-20) - sin(60) sin(-20)

What is the image of c for a 90° counterclockwise rotation about a? (3, 7) (-1, 3) (7, 3)