Please answer this one I give brainliest thank you! Number 5

The equation respenting the left table is

Prove that quadrilateral is a rhombus.

Alcoa was $10.02 a share yesterday. today it is at $9.75 a share. if you own 50 shares, did ou have capital gain or loss ? how much of a gain or loss did you have ? express the capital gain/loss as a percent of the original price