Just work this problem out backwards. First write out an equation.
(x+4)•3=30
Now solve :
(x+4)•3=30
3x+12=30
-12 -12
3x=18
/3 /3
x=6
Your answer is 6!
Hoped I helped!
You did it wrong it. It should be facing right with an open circle
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