Answer: The system of equations has NO SOLUTION.
Step-by-step explanation:
The equation of the line in Slope-Intercept form is:

Where "m" is the slope and "b" is the y-intercept.
Given the following system of equations:

Write the first equation and solve for "y" in order to express it in Slope-Intercept form:

You can identify that:

Apply the same procedure with the second equation. Then:

You can identify that:

The slopes of both lines are equal, therefore the lines are parallel and the system has NO SOLUTION.
The students would show no regard for the money being spent because it is not their money
Answer : Direct Variation
Question :
Identify the variation as direct, inverse, joint or combined. A = 
We know direct variation is y = kx
Where k is the constant of proportionality
When value of x increases then y also increases. when x value decreases then y value decreases.
The value of y depends on value of x It means y is directly proportional to x.
Hence A =
is a direct variation.
We will evaluate both expressions step by step.
Sylvia's espression:
h + 0.05h
h: Original hat price.
0.05h: Increase of 5% due to sales tax.
Jin's expressions:
1.05h
h: Original hat price.
1.05: Factor for which you must multiply the original price to add 5% due to sales tax.
30 were adults and 10 were children :) just add it up