The slope of the line is -1/7, so the perpendicular line has a slope of 7
Answer:
Total cost = charge fee + 55× no. of hours
Let h represents number of hours
Total cost = 35 + (55×h)
Note that if

, then

, and so we can collapse the system of ODEs into a linear ODE:


which is a pretty standard linear ODE with constant coefficients. We have characteristic equation

so that the characteristic solution is

Now let's suppose the particular solution is

. Then

and so

Thus the general solution for

is

and you can find the solution

by simply differentiating

.
Answer: x=13
Step-by-step explanation: