A. C = 17h + 15
b. 83 = 17h + 15
-15 - 15 subtract 15 from both sides
68 = 17h
------------
17 divide both sides by 17
4=h
They cleaned the house for 4 hours
c. C = 20x
to do this last part, you would put both equations into the calculator under y=, then look at the table to determine when the price is the same. According to the calculator, the price is the same at 5 hours
Answer:

Step-by-step explanation:

This is a homogeneous linear equation. So, assume a solution will be proportional to:

Now, substitute
into the differential equation:

Using the characteristic equation:

Factor out 

Where:

Therefore the zeros must come from the polynomial:

Solving for
:

These roots give the next solutions:

Where
and
are arbitrary constants. Now, the general solution is the sum of the previous solutions:

Using Euler's identity:


Redefine:

Since these are arbitrary constants

Now, let's find its derivative in order to find
and 

Evaluating
:

Evaluating
:

Finally, the solution is given by:
