Answer:
at least 450 minutes
Step-by-step explanation:
Find an expression for the cost of each plan as a function of the number of minutes. Set the expressions equal to each other, and solve for the number of minutes.
Let x = number of minutes.
First plan:
cost (in dollars) = 0.21x
Second plan:
cost (in dollars) = 0.11x + 44.95
Set the expressions equal:
0.21x = 0.11x + 44.95
Subtract 0.11x from both sides.
0.1x = 44.95
Divide both sides by 0.1
x = 44.95/0.1
x = 449.5
Since you cannot have a fraction of a minute, the answer is 450 minutes.
Answer:
an = -4 * (-3)^ (n-1)
513560652
Step-by-step explanation:
We can find the common ratio
12/-4 = -3
r =-3
The explicit formula is
an =a1 r^(n-1)
an = -4 * (-3)^ (n-1)
We want the 18 th term
a 18 = -4 (-3) ^ 17
513560652
The temperature would be about 54.