X = the number of minutes the phone is used
<u>Plan A:</u>
40¢ per minute ($0.40)
no other costs
<em>Cost for 1 month = 0.4 x</em>
<u>Plan B:</u>
$30 a month, even if you don't use the phone at all
100 free minutes
then 50¢ per minute ($0.50)
Cost for 1 month:
If 'x' is less than 100: <em>Cost = 30</em>
<span>
If 'x' is greater than 100</span>:
Cost = 30 + 0.5(x - 100) (Because the first 100 minutes are free, and
you only pay for minutes past 100. There are [x-100] of those.)
Eliminate parentheses: Cost = 30 + 0.5x - 50
Combine like terms: <em> Cost = 0.5x - 20</em>
Which plan costs more ? It depends on how many minutes you use in a month.
If you use a small number of minutes, Plan A costs you more.
If you use a huge number of minutes, Plan B costs you more.
Where is the crossover point ? It's the number of minutes in one month
where the costs of both plans are equal.
<u>If you use the phone for less than 100 minutes a month,</u>
(where the cost of Plan B starts increasing with each minute):
0.4x = 30
Divide each side by 0.4: <em>x = 75</em>
Less than 75 minutes per month, Plan A costs less.
Past 75 minutes a month, Plan A costs more than $30, so Plan B costs less,
until Plan B starts charging for extra minutes.
<u>If you use the phone for more than 100 minutes a month: </u>
0.4 x = 0.5 x - 20
Add 20 to each side: 0.4 x + 20 = 0.5 x
Subtract 0.4x from each side: 20 = 0.1 x
Multiply each side by 10: <em> 200 = x</em>
There it is.
Now we can combine the results:
-- Less than 75 minutes in a month: Plan A costs less.
-- Between 75-200 minutes in a month: Plan B costs less.
-- More than 200 minutes a month: Plan A costs less again.
Complicated ? Absolutely ! That's why citizens' consumer groups are after
these companies, to try to get them to make their plans more understandable
to regular people. I know from personal experience that even a lot of the
salesmen in the phone stores could not figure this out and give you sound advice.
Answer:
See below
Step-by-step explanation:
The first two questions are slope = 0
a horizontal line has zero slope
slope = rise/run = 0 / run = 0
Greatest y value is + 4 from x = 3 to 4
the least y value is -3 fro x = -4 to -3
Answer:
0 < y <= 6
Step-by-step explanation:
Given:
√(x² - 6x + 9)
if -3 <= x < 3
you can write (x² - 6x + 9)
as (x-3) * (x- 3) which is (x-3)²
so now you have √{(x-3)²}, which is the same as the absolute value of x-3. In mathematics it is written as:
| x - 3 |
So √(x² - 6x + 9) = | x - 3 |
See the graph in the attachment.
for -3 <= x < 3
you get the y values bigger then ( but not equal to) 0 and smaller then or equal to 6.
This is written as 0 < y <= 6
Answer:
22
Step-by-step explanation:
Given:
An art teacher has the total number of buttons = 
1. In order to give each in the class 6 buttons, she will need 18 more buttons.
2. If she gives each child 5 buttons, she will have 4 left over.
Question asked:
How many children are in the class ?
Solution:
<u>Let total number of children in the class = </u>
<u><em>As given that, 18 more buttons will be needed to give 6 buttons to each.</em></u>
The equation will be:-

<em><u>Also given that, If she gives 5 buttons to each, she will have 4 left over.</u></em>
The equation will be:-

Subtraction equation 2 from 1

Hence, total number of children are 22.