Answer: OPTION D.
Step-by-step explanation:
For this exercise it is important to remember that:
1. Direct proportion equations have the following form:

Where "k" is the constant of proportionality.
2. The graph of Direct proportions is an straight line that passes through the origin.
Observe the picture attached.
If you join the points G, C and A, you get a straight line that passes through the origin,
If you join the points F, G and H, you also get a straight line that passes through the origin,
Therefore, the sets of points show "x" in Direct proportion to "y", are:
and
Question:
Find the constant of proportionality k. Then write an equation for the relationship between x and y

Answer:
(a) 
(b) 
Step-by-step explanation:
Given

Solving (a): The constant of proportionality:
Pick any two corresponding x and y values


The constant of proportionality k is:




Solving (b): The equation
In (a), we have:

k can also be expressed as:

Substitute values for x1, y1 and k

Cross multiply:

Open bracket

Add 10 to both sides


12.89 can be written as 1289/100, hence its a rational number.
Answer:
b: y=1/4x -2
Step-by-step explanation:
It says the answer in the question. the slope on the graph is really just 1 though.