D is a notation for differential. There is a d2 in your formula because in the numerator there are two differentials. The formula is thus the second derivative of a function with respect to two variables.
The answer is 11 degrees if you want to know why this is the answer reply to my comment
Answer:
m = 300
Step-by-step explanation:
multiply both sides of the equation by 5
This could be written as y= -2x+6 in standard form