Sum of an infinite geometric sequence with the common ratio r, and the first term a1 is

we notice
-2 times -1/4=1/2,
1/2 times -1/4=-1/8
so a1=-2
r=-1/4 or -0.25
so the sum is

=

=

=

=
the sum is -8/5 or -1.6
You find circumference w the diameter given
equation
circumference- 2(pie)R (use the pie symbol)
Using linear functions, it is found that the two plans cost the same for 5000 minutes of calling.
<h3>What is a linear function?</h3>
A linear function is modeled by:

In which:
- m is the slope, which is the rate of change, that is, by how much y changes when x changes by 1.
- b is the y-intercept, which is the value of y when x = 0.
For Plan A, the cost is of $25 plus an additional $0.09 for each minute of calls, hence the y-intercept is
, the slope is of
, and the function is:

For Plan B, the cost is of $0.14 for each minute of calls, hence the y-intercept is
, the slope is of
, and the function is:

The plans cost the same for x minutes of calling, considering that:





The two plans cost the same for 5000 minutes of calling.
To learn more about linear functions, you can take a look at brainly.com/question/24808124
Answer:
y= -2x/3+8
Step-by-step explanation:
find 2 points: (0,8) and (6,4)
substitute in y=ax+b
8=0a+b
b=8
4=6a+b
4=6a+8
6a=-4
a=-2/3