Answer:
56.42 minutes
Step-by-step explanation:
The initial sample= y0 = 800
After 13 minutes , amount = 320
Y= y0e-kt
320 = 800e-k(13)
320/800 = e-k13
0.4 = e-k13
In0.4 = -k13
-0.91629= -k13
0.07048= k
Y = 800e-0.07048t
Minutes when the bacterial present will be 15
15 = 800e-0.07048t
15/800= e-0.07048t
0.01875 = e-0.07048t
In 0.01875 = -0.07048t
-3.97656 = -0.07048t
-3.97656/-0.07048= t
56.42 = t
56.42 minutes
An exponential function displays either a growth or decay behavior going from a low steep to a high steep.
Answer:
Its D
Step-by-step explanation: Since the answer choices B and C don't make sense, its between A and D.
A is actually wrong since it said that the lower class benefited protection from these lords and serfs. Also, the last two lines support D.
I am unsure about the very last problem but I can help with the first two
1) (y+1)+4
If we combine the numbers 1 and 4, we get +5 and can isolate the numbers from the variable.
This would give us

2) (6*r)*7
remember that we do not have to explicitly state 6*r
Instead, we can write it as 6r
this helps us get rid of the parentheses
now we can write it as

I hope this helps!:)
Answer:
x=4
Step-by-step explanation:
tangent lines from the same point to a circle are congruent in length, so we can say that
5x+8 = 8x-4
5x -5x +8 = 8x - 5x -4
8 = 3x - 4
8+4 = 3x -4 + 4
3x = 12
3x/3 = 12/3
x=4