Answer:

Step-by-step explanation:
Suppose the electrician spends t hours at the house working.
Amount charged for every house call by electrician = $50
The electrician earned a total of $400 for a 5 hour job.
Also, C denotes total cost of the electrician's services.
So, the equation for C in terms of t is given below.

Here, 
A hand generator it most likely will provide power to perform wok more efficiently.
<h3>A hand generator and a 9v battery</h3>
Generally, A hand generator is a portable device that use energy to do work or increase efficiency of work done.
Therefore,if a 9v battery( a battery is defined as a source of electric power) is attached to a hand generator it most likely will provide power to perform wok more efficiently
For more information on work
brainly.com/question/756198
The circumcenter of a right angled triangle is midpoint of the hypotenuse side.
Determine the midpoint of the hypotenuse.

For y coordinate,

So, circumcenter of triangle is,
Answer:
Choice 'D' (10x + 9) (10x-9) is the correct answer
Step-by-step explanation:
100x^2 - 81
This is a difference of squares...
therefore = (10x + 9) (10x - 9)