No question is asked so I'm not sure what you are looking for but below I calculated the point where the two equations intersect:
y - x = 4 → y = x + 4
y = - x² + 6x
x + 4 = - x² + 6x
x² - 5x + 4 = 0
(x - 4)(x - 1) = 0
x = 4, x = 1
when x = 4, then y = x + 4 = 4 + 4 = 8 → (4,8)
when x = 1, then y = x + 4 = 1 + 4 = 5 → (1,5)
The line and parabola intersect at two points: (4,8) and (1,5)
The type of graph that would allow us to quickly see how many students were treated would be a Bar graph.
Step 1: Find the slope:

This gives you
, but we need to find b.
To find b, substitute in one (x,y) pair and it doesn't matter which one. I'll go with (4,-2):
![\begin{aligned}-2&=-\dfrac{3}{2}(4)+b\\[0.5em]-2&=-6+b\\[0.5em]4&=b\end{aligned}](https://tex.z-dn.net/?f=%5Cbegin%7Baligned%7D-2%26%3D-%5Cdfrac%7B3%7D%7B2%7D%284%29%2Bb%5C%5C%5B0.5em%5D-2%26%3D-6%2Bb%5C%5C%5B0.5em%5D4%26%3Db%5Cend%7Baligned%7D)
Now take that b-value and plug in into the slope-intercept form:

It's always a good idea to toss in the other x-value from the other point, to make sure it checks out.
Answer:
ERIC HAD 12 PIECES OF CLAY LEFT
Step-by-step explanation:
1/3 + 4 = 12