Since it is linear, we can find a linear equation to represent the relationship. We have two points (3,6) and (11,15). The slope is 9/8. So we have an equation:
y = (9/8)x + b
Plug in (3,6) to find out that b = 21/8
So our equation that represents this linear relationship is:
y = (9/8)x + 21/8
Now to figure out what "p" is, we plug in x = -1, and we get p = 1.5
To figure out what "q" is, we plug in x = 7, and we get q = 10.5
Therefore the sum of p and q:
1.5 + 10.5 = 12
