A cell phone plan costs $79 per month for 500 minutes. For each minute over 500, the customer is charged an additional $.20 per minute. Which equation can be used to calculate the monthly bill, y, if a person talked for x minutes over 500 in a month?

$.20 × (x) + $79

Step-by-step explanation:

To find out how much needs to be paid, subtract the 500 from the total amount of minutes used to find the amount of minutes used over 500. Then, multiply the additional minute cost by the additional minutes and the add the normal price to that.

Say they used 560 minutes in a month. You would subtract 500 from 560 to get to get 60. Then, you would multiply 60 by $.20 to get $12. Then, add $12 to the original price of $79 to get $91, and that would be the total cost that month.

560 - 500 = 60 × $.20 = $12 + $79 = $91

geometric series converge the common ratio r has magnitude less than one.

which is equivalent to

for the example we need

|2-x| < 1

-1 < 2-x   and 2-x < 1

x < 3 and x > 1

we can write that

answer: 1 < x < 3

1a. common ratio r=250/25=10 > 1     diverges

1b.   r=50/100=1/2 converges

when these converge they converge to

where a is the first term.

answer: 200

1c. r=-1   so it's not the case that |r| < 1.     diverges

2a. x is the common ratio so we converge when |x|< 1

2b.   r=-10x / -2 = 5x.

we converge when

|5x| < 1

|x| < 1/5

2c.   r=3-2x

-1 < 3-2x and 3-2x < 1

-4 < -2x and 2 < 2x

x < 2 and 1 < x

1 < x < 2

2d. [/tex] r=-48x^3/12 = 4x^3[/tex]

|4x^3| < 1

|x^3| < \frac 1 4

|x| < 4^{-1/3}

the first option is the answer.