Sum of the terms of the series is
Sn = n/2 ( a1+an )
we have n= 6 , a1= 17, an = 57
so Sn = 6/2 ( 17+57) = 3(74) = 222
Answer:
$43.4
Step-by-step explanation:
Let's say x is the cost per kilgram
30x = 93
x = 3.1
14x = 43.4
They will make the same amount after 10 phones sold. Before that Plan A is the better plan. After 10, Plan B is the better plan.
You can find the point of intersection by modelling the two equations and setting them equal to each other. If x is equal to phones sold:
250 + 25x = 50x
250 = 25x
10 = x
Therefore, you make the same at 10 phones.
Answer:
p = -2 ±sqrt( 5)
Step-by-step explanation:
p^2 + 4p = 1
Take the coefficient of p
4
Divide by 2
4/2 =2
Square it
2^2 = 4
Add it to each side
p^2 + 4p+4 = 1+4
(p+2) ^2 = 5
Take the square root of each side
sqrt((p+2) ^2) =±sqrt( 5)
p+2 = ±sqrt( 5)
Subtract 2 from each side
p+2-2 = -2 ±sqrt( 5)
p = -2 ±sqrt( 5)
