Okay, let's see...
The problem is asking for a linear equation most likely in the form of y=mx+b
y is another way to say f(x)
<em>m = slope </em>
<em>b = y intercept </em>
Let's start with the y intercept first.
Y intercept means ' When does the line touch (intercept) the y axis.
In this case, if you look at the graph, the line <em>touches </em>the y axis at -1.
-1 will replaces b
To find the slope we are going to take 2 precise points from the graph.
Lets use <em>(0,-1)</em> and <em>(-6,4) </em>
To find the slope, we're going to use 
4 - (-1) / -6 - 0
Solve, our slope is 5/-6
That is our m
Our final equation is
The length of the rectangle is = 72 cm
The width of the rectangle is = 56 cm
Area of the rectangle is = 
= 
cm²
As given, the other rectangle has the same area as this one, but its width is 21 cm.
Let the length here be = x
Hence, length is 192 cm.
We can see that as width decreases, the length increases if area is constant and when length decreases then width increases if area is constant.
So, in the new rectangle,constant of variation=k is given by,
or 
Hence, the constant of variation is 
Answer: To solve these types of questions what I always do is get a protractor if you have one and put it up against to where the dot is in the middle of the empty hole and then get a ruler or a pencil and make the line keep going to see what angle. In this case your answer is 65% I think.
