Answer:
As the depth decreases. the temperature of the water increases.
Step-by-step explanation:
The graph is showing the depth increasing (to the right) and the temperature decreasing (down).
1.

or if you mean (3x^3+5x^2+3x-7)+(8x-6x^2+6):

2.

step 2 would be 10
step 4 would be 10x-x = 9x =7
x = 7/9
The answer is 1,4 therefore y = 1x - 4
Because if you ask one student from each class you are getting a more accurate representation of the classes. If you were to ask one group you'd only get their opinion