Answer:
An appositive (or an appositive phrase) gives more information about a noun. The appositive is usually placed next to the noun it modifies. Writers use appositive and appositive phrases in order to provide more information about something.
Explanation:
It’s the steepness of a line
+slope
Economy in english, oikonomos in greek
It seems that you have already filled the correct pronoun in the blank provided. Yes, the correct answer to complete this sentence is the pronoun "this". The pronoun "this" is an example of a demonstrative pronoun. Other demonstrative pronouns also include these, those, and that. Hope this answer helps.