Pls help I don't know how to do this​

Vertex, I believe.

Vertex

Step-by-step explanation:

A vertex (or node) of a graph is one of the objects that are connected together. The connections between the vertices are called edges or links. A graph with 10 vertices (or nodes) and 11 edges (links).

part a:

house 1 function is exponential

house 2 function is linear

explanation:

house 1 value is increasing by 4% each year

house 2 value is increasing by 11,000 each year

part b:

house 1 function:   f(x)=179000(1.04)^x

house 2 function: f(x)=179000+11000(x)

part c:

house 1: f(30)=580568.15

house 2: f(30)=509000

580568-509000=71568 thus, house 1 yields a better roi (return on investment)