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Leya [2.2K]
3 years ago
12

What is a negative control.

Mathematics
1 answer:
OLga [1]3 years ago
7 0

Answer:

Negative controls are particular samples included in the experiment that are treated the same as all the other samples but are not expected to change due to any variable in the experiment.

Step-by-step explanation:

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Rename 476,000 thousands
lozanna [386]

Answer:

Four hundred seventy six thousand

Step-by-step explanation:

I think this is what you mean. If not, let me know. Thank you:))

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3 years ago
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What is 9 tens more than 99 190​
Oksana_A [137]
99 plus 9 tens?? if so, 189
5 0
3 years ago
How much pure water must be mixed with 10 liters of a 25% acid solution to reduce it to a 10% acid solution?
Alex73 [517]
The solution is 25% acid, which means 2.5 liters acid (10 x .25). 
<span>you need that 2.5 liters to be 10%, or 1/10th the total. </span>
<span>the total would have to be 25 liters (2.5 x 10) so when you add to 10 to get 25 you get </span><span>15 liters. Hope I helped!</span>
3 0
3 years ago
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If N is the population of the colony and t is the time in​ days, express N as a function of t. Consider Upper N 0 is the origina
lesya [120]

Answer:

(a)N(t)=Noe^{kt}

(b)5,832 Mosquitoes

(c)5 days

Step-by-step explanation:

(a)Given an original amount N_o at t=0. The population of the colony with a growth rate k \neq 0, where k is a constant is given as:

N(t)=Noe^{kt}

(b)If N_o=1000 and the population after 1 day, N(1)=1800

Then, from our model:

N(1)=1800

1800=1000e^{k}\\$Divide both sides by 1000\\e^{k}=1.8\\$Take the natural logarithm of both sides\\k=ln(1.8)

Therefore, our model is:

N(t)=1000e^{t*ln(1.8)}\\N(t)=1000\cdot1.8^t

In 3 days time

N(3)=1000\cdot1.8^3=5832

The population of mosquitoes in 3 days time will be approximately 5832.

(c)If the population N(t)=20,000,we want to determine how many days it takes to attain that value.

From our model

N(t)=1000\cdot1.8^t\\20000=1000\cdot1.8^t\\$Divide both sides by 1000\\20=1.8^t\\$Convert to logarithm form\\Log_{1.8}20=t\\\frac{Log 20}{Log 1.8}=t\\ t=5.097\approx 5\; days

In approximately 5 days, the population of mosquitoes will be 20,000.

7 0
3 years ago
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Find the equation of the line specified. The slope is -7, and it passes through ( 5, -3).
Montano1993 [528]
The general equation of a line is
y= ax + b
where a is the slope
So a = -7
So y= -7x + b
But it passes through the point (5, -3)
Substitute the coordinates to calculate b:
So -3 = -7(5) + b
-3 = -35 + b
b= 35-3
b= 32
So the equation of the line of slope -7 and passing through the point (5, -3) is
y= -7x + 32
7 0
3 years ago
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