Note: It seems you may have unintentionally missed writing the complete question. As total cost is missing.
So, I am assuming how many tickets Mr. XYZ can buy if he/she pays 530 dollars.
The solution would still clear your concept though.
Answer:
Please check the explanation.
Explanation:
Given the function
c(x) = 18x -10
The slope-intercept form of the line equation
We know that the slope-intercept form of the line equation

where m is the slope and b is the y-intercept
so
c(x) = 18x - 10
comparing with the slope-intercept form of the line equation
- c(x) or y represents the cost
- 'x' represents the number of tickets
Assuming the total cost i.e. c(x) = $530
In order to determine the value of x, set c(x) = 530
i.e.
530 = 18x -10
switch sides
18x - 10 = 530
add 10 to both sides
18x - 10 + 10 = 530 + 10
18x = 540
Divide 18 to both sides
18x/18 = 540/18
x = 30
Therefore, if you can buy x = 30 tickets if you pay 530 dollars.