What is halfway between 5.3 and 5.4

Me, prove a quadrilateral with vertices g(1,-1), h(5,1), i(4,3) and j(0,1) is a rectangle using the parallelogram method and a rectangle method.

Find the area of a parallelogram with base 15 yards and height 21 2/3

If you are trying to move an attached term across the equal sign (=), what operation would you use to move it?