Answer:
a. 
b. 
c. 
d.
minutos
Step-by-step explanation:
a. Newton's law of cooling states that the speed with which a body is cooled is proportional to the difference between its temperature and that of the medium in which it is found. Then, the initial value problem is given by:


b. The differential equation obtained is a differential equation of separable variables:

c. After 33 minutes of serving the coffee has cooled to 180°:

d.

Answer:
See attached picture.
Step-by-step explanation:
To graph linear inequalities, use the y=mx + b form to graph using the slope and y-intercept.
y ≤ -4x + 40 has slope -4 and y-intercept (0,40).
Start at (0,40) and mark it. Then move down 4 units and to the right 1. Mark this point at (1,36). Connect the points with a solid line since the inequality has equal to. Substitute a point like (0,0) to test where the solution set is.
0 ≤ -4(0) + 40
0 ≤ 0 + 40
0 ≤ 40
This is true so shade to the left of the line.
To graph y ≤ 10 mark a point on the y-axis at (0,10). Draw a horizontal solid line through the point. Then shade below the line.