I really do not understand this and of course I need to by a few hours from now. If any one can help I would really appreciate it!

I have an area enclosed by y = 3x and y = x^2 with x greater than or equal to 1 and less than or equal to 2

I need to find the mass of the region and then find the moment about the x axis and the moment about the y axis.

Thanks for all the help I have received this term!!!!!