Sagot :
The problem here is that you need to find what is the monthly fee for the telephone + the fee per minute.
Data we are looking for:
x - subscription plan
y - rate per minute
1. Finding the monthly fee (x) + rate per minute (y)
x + 150y = 45.50
x + 100y = 38.00
you have to deduct those equatations (x - x = 0, 150y - 100y = 50y, 45.5 - 38 = 7.5)
- finding rate per minute:
50y = 7.50
5y = 0.75
y = 0.15
- finding monthly fee
x + 150 *0.15 = 45.50
x = 45.50 - 22.50
x = 23.00
Looking at the data above you can see that no matter for how many minutes you use your phone you have to pay 23$. For every minute you spend talking the fee is 0.15$
That is why (z) the total amount you have to pay consist of 23 (subscription) + 0.15y (15c per minute):
z = 23 + 0.15y
Add a comment if sth is not clear
Data we are looking for:
x - subscription plan
y - rate per minute
1. Finding the monthly fee (x) + rate per minute (y)
x + 150y = 45.50
x + 100y = 38.00
you have to deduct those equatations (x - x = 0, 150y - 100y = 50y, 45.5 - 38 = 7.5)
- finding rate per minute:
50y = 7.50
5y = 0.75
y = 0.15
- finding monthly fee
x + 150 *0.15 = 45.50
x = 45.50 - 22.50
x = 23.00
Looking at the data above you can see that no matter for how many minutes you use your phone you have to pay 23$. For every minute you spend talking the fee is 0.15$
That is why (z) the total amount you have to pay consist of 23 (subscription) + 0.15y (15c per minute):
z = 23 + 0.15y
Add a comment if sth is not clear
Answer:
Step-by-step explanation:
We can make 2 simultaneous equations and solve for the set fee
and the per minute charge:
Let x = fixed monthly rate
Let m = per minute charge
x + 100m = 135 {equation 1}
x + 500m = 375 {equation 2}
subtract equation 1 from equation 2
400m = 240
m = 0.6
substitute that back into equation 1 or 2 to solve for x.
Using equation 1
x + 100(.6) = 135
x + 60 = 135
x = 75
The fixed monthly rate is $75
The per minute charge is $0.6
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If y is the total cost for a month and x is the
number of minutes used the equation is:
y = 0.6x + 75