Answer:
<h2>A. cost of materials.</h2><h2>C. number of hours.</h2>
Step-by-step explanation:
The given expression is

This is a linear expression in slope-intercept form, where the constant ratio of change is 30, and the y-intercept is at y = 65.
Now, according to the problem, the expression represents the hourly charges, including the cost for the materials.
Therefore, the hourly charge is $30 per hour, where x represents hours, and the cost for materials is $65.
So, the answer to the first question is: A. cost of materials.
And the answer to the second question is: C. number of hours.