7. ( 35 pts) Let R represent the region in the first quadrant bounded by X= 1, y= 12, and y= 3x . The mass density at each point in R is 5 grams per square centimeter. Also, let Q denote the solid created by revolving R about the x-axis. After sketching R, set up definite integrals that equal: as the mass of R; bi my of R; c) x of R ; di the volume of