Answer:
3.85 hours
Step-by-step explanation:
We have that the model equation in this case would be of the following type, being "and" the concentration of bacteria:
y = a * e ^ (b * t)
where a and b are constants and t is time.
We know that when the time is 0, we know that there are 100,000 bacteria, therefore:
100000 = a * e ^ (b * 0)
100000 = a * 1
a = 100000
they tell us that when the time is 2 hours, the amount doubles, that is:
200000 = a * e ^ (b * 2)
already knowing that a equals 100,000
e ^ (b * 2) = 2
b * 2 = ln 2
b = (ln 2) / 2
b = 0.3465
Having the value of the constants, we will calculate the value of the time when there are 380000, that is:
380000 = 100000 * (e ^ 0.3465 * t)
3.8 = e ^ 0.3465 * t
ln 3.8 = 0.3465 * t
t = 1.335 / 0.3465
t = 3.85
That is to say that in order to reach this concentration 3.85 hours must pass
Answer:26
Step-by-step explanation:
Y=1.25^x-2/5-10
Take log of both sides
So Y+10=1.25^x-2/5
So log to base 10 of the two sides of the equation is
Log(Y+10)=X-2/5log1.25.
To make X the subject, divide both sides by log1.25.
Log(Y+10)/log1.25=X-2/5.
Recall that Y was given to be 115
It becomes log(115 +10)/Log1.25=x-0.4
21.64=x-0.4
X=25.6
Can't understand the sentence where it says "<span>From the ground, Todd's used to plane moving directly toward him from the West at a 49 degree angle of elevation". Help me interpret it.</span>
Answer:
BC = 26
Step-by-step explanation:
Given that:
B is the midpoint of AC
Then AC = AB + BC
AC = 8x - 20 and AB = 3x - 1
Then,
8x - 20 = (3x - 1) + BC
8x - 20 - (3x - 1) = BC
8x - 20 - 3x + 1 = BC
5x - 19 = BC
But AB = BC
5x - 19 = 3x - 1
5x - 3x = - 1 + 19
2x = 18
x = 9
Hence,
Since BC = AB = 3x - 1
3(9) - 1
27 - 1
= 26
