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:

The answer to this is 720000
<span>3x+5y= 12
5y = 12 -3x
y = (12-3x)/5
y = 12/5 - 3x/5
y = 2.4 -0.6x
or
y = -0.6x + 2.4</span>
Answer:
Step-by-step explanation:
Let the numbers be x and y.
<u>The equations are:</u>
<u>Add up the equations to eliminate y and solve for x:</u>
- x - y + 2x + y = 2 + 13
- 3x = 15
- x = 15/3
- x = 5
<u>Now find the value of y:</u>
- y = x - 2
- y = 5 - 2
- y = 3