I think you meant the two <em>segments</em><em> </em>are identical, if so then:

Must be simplified. don;'t really know if we should do distributive property
A pure substance that is made of only one kind of atom is called an element.
An element is a pure substance, which means it is made up of only ONE kind of atom.
Y-intercept: (0,-3)
x-intercept: (0,5)
Length times width times height