Answer:

Step-by-step explanation:
Hi!
Lets call:
T = temprature of the object
T₀ = temperature of surroundings
t = time
The rate of change of T is its derivative with respecto to time. If T > T₀, the object looses heat, so T decreases. Then, being k > 0:

In this case T₀ = 70ºF and k = 0.05/min. Then the differential equation is:

We have
-9 + 7 = -2
You can also rewrite this as
7 - 9 = -2
If it makes you more comfortable.
Hope this helps.
Answer:
B. c = fλ
Step-by-step explanation:
The given equation is

To solve for c you must multiply both sides of the equation by lambda.

Answer:
-19
Step-by-step explanation:
Answer:
-12π
Step-by-step explanation: