we are given that
f(x) is defined for all values of x except at x=c
Limit may or may not exist
case-1:
If there is hole at x=c , then limit exist
case-2:
If there is vertical asymptote at x=c , then limit does not exist
Examples:
case-1:

We can simplify it



so, we can see that limit exist and it's value defined
case-2:

Left limit is


Right Limit is


so, we can see that left limit is not equal to right limit
so, limit does not exist
Answer:
what is the question because I don't understand what you mean
Answer:
Step-by-step explanation:
Let the equal number of hours be represented by variable H;
The two equations will be as follows;
Jack; 40 +30H
Mark; 50 +25H
Next, equate them;
40 + 30H = 50 + 25H
30H - 25H = 50 - 40
5H = 10
H =10/5
H = 2hrs
Therefore, they charge the same amount at 2 hrs.
B.) The amount charged;
Replace the variable H in any of the two equations above with 2 to solve for the amount.
Equation 40+30H = 40 + (30*2)
=40 + 60
= $100