If we know the cost of a ticket is $7, we can then write an equation in slope-intercept form for the amount it will cost to buy any amount of tickets.
If we denote x as the amount of tickets purchased, and c as the total cost, we can write the equation:

Since we can vary the amount of tickets purchased independently of the total amount, x (the amount of tickets purchased) will be the independent variable.
However, since y (the total cost) is directly dependent on the amount of tickets that are purchased, c is the dependent variable.
For scientific notation, you always want 1 digits in front of the decimal.
Ex) 7.39*10^5
Move the decimal point in between the 1 and 4, or 1 place to the left.
1.435
Since the decimal point was moved 1 place to the left, the exponent after 10 will be 1.
1.435*10^1
1.435*10^1 is your final answer.
1.435*10 is the same thing also.
5/12 = 0.4166666...
That is what it says on the calculator.
The answer is 1,80 because it would be the sequence