How is the series 4 + 9 + 14 t... + 194 represented in summation notation?

Each number is 5 units in between and can be used by the following equation 4+5x.

the cost of plan A would be lesser than that of plan B for minutes lesser than 470

Step-by-step explanation:

Let m represent the number of minutes of monthly phone used.

In plan A the customer pays a monthly fee of $25 and then an additional 6 cents per minute of use. It means that the total cost of using m minutes in a month is

0.06m + 25

In plan B the customer pays a monthly fee of $29.70 and then an additional 5 cents per minute of use. It means that the total cost of using m minutes in a month is

0.05m + 29.7

The inequality representing the number of minutes of monthly phone use for which Plan A will cost less than Plan B is

0.06m + 25 < 0.05m + 29.7

0.06m - 0.05m < 29.7 - 25

0.01m < 4.7

m < 4.7/0.01

m < 470