Answer:
The monthly cost for 45 minutes is $18.42
Step-by-step explanation:
Let
x -----> the total calling time in minutes
y ----> the monthly cost in dollars
we have the ordered pairs
(42,18.15) and (90,22.47)
step 1
Find the slope
The formula to calculate the slope between two points is equal to
substitute the values
step 2
Find the linear equation in point slope form
![y-y1=m(x-x1)](https://tex.z-dn.net/?f=y-y1%3Dm%28x-x1%29)
we have
![m=0.09\\(x1,y1)=(42,18.15)](https://tex.z-dn.net/?f=m%3D0.09%5C%5C%28x1%2Cy1%29%3D%2842%2C18.15%29)
substitute
![y-18.15=0.09(x-42)](https://tex.z-dn.net/?f=y-18.15%3D0.09%28x-42%29)
step 3
Find the monthly cost for 45 minutes of calls
For x=45 min
substitute the value of x in the linear equation and solve for y
![y-18.15=0.09(45-42)](https://tex.z-dn.net/?f=y-18.15%3D0.09%2845-42%29)
![y-18.15=0.09(3)](https://tex.z-dn.net/?f=y-18.15%3D0.09%283%29)
![y-18.15=0.27](https://tex.z-dn.net/?f=y-18.15%3D0.27)
![y=0.27+18.15](https://tex.z-dn.net/?f=y%3D0.27%2B18.15)
![y=18.42](https://tex.z-dn.net/?f=y%3D18.42)
therefore
The monthly cost for 45 minutes is $18.42
Answer:
$70
Step-by-step explanation:
Daria's total income = fixed income + variable income
Let
Daria's Fixed income = x
additional $30 if the buyer gets an extended warranty
Daria's variable income = 30s
Where,
s = number of televisions with extended warranties she sells
If Daria sells 15 televisions with extended warranties, she earns \$1,500. Find her fixed income
Daria's total income = fixed income + variable income
1500 = x + 30(15)
1500 = x + 450
1500 - 450 = x
1,050 = x
x = $1,050
Daria's total fixed income = $1,050
How much is the fixed amount Daria for each television?
Fixed income per television = Total fixed income / number of television sold
= 1050 / 15
= 70
Fixed income per television = $70
Answer:
(x,y) = (-36,6)
Step-by-step explanation:
-6y=x
x+y=-30
x=-6y,
so -6y+y=-30
-5y=-30
y=6
x=-36
Hope this helps pls hit the crown :D
Using the quadratic equation we get:
![\frac{ - 2 + - \sqrt{4 - 32} }{2} = \frac{ - 2 + - \sqrt{ - 28} }{2}](https://tex.z-dn.net/?f=%20%5Cfrac%7B%20-%202%20%2B%20-%20%5Csqrt%7B4%20-%2032%7D%20%7D%7B2%7D%20%3D%20%5Cfrac%7B%20-%202%20%2B%20-%20%5Csqrt%7B%20-%2028%7D%20%7D%7B2%7D%20)
Factoring out 2 we get
![\frac{ - 2 + - 2\sqrt{ - 7} }{2} = - 1( + - ) \sqrt{ - 7}](https://tex.z-dn.net/?f=%20%5Cfrac%7B%20-%202%20%2B%20-%202%5Csqrt%7B%20-%207%7D%20%7D%7B2%7D%20%3D%20-%201%28%20%2B%20-%20%29%20%5Csqrt%7B%20-%207%7D%20)
Factoring out the imaginary number:
![- 1 + \sqrt{7} i \: (and) \: - 1 - \sqrt{7} i](https://tex.z-dn.net/?f=%20-%201%20%2B%20%5Csqrt%7B7%7D%20i%20%5C%3A%20%28and%29%20%5C%3A%20-%201%20-%20%5Csqrt%7B7%7D%20i)
So b.