Answer: x = 1.50551927,2.68790604
Step-by-step explanation:
Horizontal cross sections are the same shape: they are all squares if the pyramid is square or rectangles if the pyramid is a rectangle pyramid.
Vertical cross sections are different shape: At the pyramid top they are triangles, at other places they have four sides.
Horizontal cross sections are different size: the more we go to the top of the pyramind, the smaller they get.
Vertical cross sections are different size: the closer we get to the edges, the smaller they become.

Multiply 50 by 0.90 because you take a discount of 10% off. 1.00 = 100% 0.10 = 10% 0.01 = 1% if you multiply 50 by 0.10 instead you get the amount that is discounted instead of the new selling price.
If Carly had more DVDs than Rob then you would subtract her amount away from the total. 42-4=38