Answer:
Part A : E = 35h + 200
Part B : The per hour charges of the technician is $35/hour.
Explanation:
The technician observes that his earnings are a linear function of the number of hours he works during the month. The technician finds that when he works 55 hours during the month, he earns $2,125 and when he works 30 hours, he earns $1,250 .
If we consider the number of hours that he works in a month is h and the amount he earns in dollars is E, then (30,1250) and (55,2125) are the two ordered pairs.
Part A : Therefore, the linear function to model the relationship between the number of hours worked and the money earned will be

⇒ E - 2125 = 35(h - 55)
⇒ E - 2125 = 35h - 1925
⇒ E = 35h + 200
Part B : The equation above is in the slope-intercept form and the slope is 35 which means that the per hour charge of the technician is $35/hour. (Answer)