All categories

3 years ago

A scientist creates a colony of bacteria in a dish. This type of

Mathematics

1 answer:

ryzh [129]3 years ago

6 0

Answer: 9:14

Step-by-step explanation: So if he started if 1 bacteria, it becomes 2 bacteria at 9:01, etc. So at 9:13, it is 2^13 and if that is half, that means 2^14 is when it is full so 9:14.

You might be interested in

I’m not sure what to do..

Arlecino [84]

Answer:

x=291/76

Step-by-step explanation:

Convert:

1/2x(6x+ 1/2)=-0.8x+16-1.2

Remove parenthesis and move terms:

3x+1/4=-0.8x+14.8

Collect the like terms and convert:

3x+0.8x=14.8-1/4

Subtract the fractions:

3.8x=74/5-1/4

Divide both sides by 3.8:

3.8x=291/20

x=291/76

7 0

3 years ago

Ratio of 25cm to 40cm

BARSIC [14]

5:8

is the ratio .he she and shd

6 0

2 years ago

!!!!!!!!!!!!Please help!!!!!!!!!!!!!!

aksik [14]

Answer:

The answer to your question is a) (f°g)(x) = 4x² + 2

b) (f + g)(x) = 4x² + x + 2

c) (f - g)(-3) = -37

Step-by-step explanation:

Data

f(x) = x + 2

g(x) = 4x²

a) Calculate (f°g)(x)

Just sum the function

(f°g)(x) = (4x²) + 2

-Simplification

(f°g)(x) = 4x² + 2

b) (f + g)(x)

(f + g)(x) = x + 2 + 4x²

-Simplification

(f + g)(x) = 4x² + x + 2

c) (f - g)(-3)

-Calculate (f - g)(x)

(f - g)(x) = x + 2 - 4x²

-Simplify

(f - g)(x) = -4x² + x + 2

-Evaluate in (-3)

(f - g)(-3) = -(4)(-3)² + (-3) + 2

-Simplification

(f - g)(-3) = -4(9) - 3 + 2

-Result

(f - g)(-3) = -36 - 3 + 2

(f - g)(-3) = -37

5 0

3 years ago

A tank initially has 300 gallons of a solution that contains 50 lb. of dissolved salt. A brine solution with a concentration of

belka [17]

Let s(t) be the amount of salt in the tank at time t. Then s(0) = 50 lb.

Salt flows into the tank at a rate of

(2 gal/min) (6 lb/gal) = 12 lb/min

and flows out at a rate of

(2 gal/min) (s(t)/300 lb/gal) = s(t)/150 lb/min

so that the net rate at which salt is exchanged through the tank is

ds(t)/dt = 12 - s(t)/150 … (lb/min)

Solve for s(t). The DE is separable, so we have

ds/dt = 12 - s/150

150 ds/dt = 1800 - s

150/(1800 - s) ds = dt

Integrate both sides to get

-150 ln|1800 - s| = t + C

Solve for s :

ln|1800 - s| = -t/150 + C

1800 - s = exp(-t/150 + C )

1800 - s = C exp(-t/150)

s = 1800 - C exp(-t/150)

Now given that s(0) = 50, we solve for C :

50 = 1800 - C exp(-0/150)

50 = 1800 - C

C = 1750

Then the amount of salt in the tank at any time t ≥ 0 is

s(t) = 1800 - 1750 exp(-t/150)

To find the time it takes for the tank to hold 100 lb of salt, solve for t in

100 = 1800 - 1750 exp(-t/150)

1700 = 1750 exp(-t/150)

34/35 = exp(-t/150)

ln(34/35) = -t/150

t = -150 ln(34/35) ≈ 4.348

So it would take approximately 4.348 minutes.

By the way, we didn't have to solve for s(t), we could have instead stopped with

-150 ln|1800 - s| = t + C

Solve for C - this C is not the same as the one we found using the other method. s(0) = 50, so

-150 ln|1800 - 50| = 0 + C

C = -150 ln|1750|

==> t = 150 ln(1750) - 150 ln|1800 - s|

Then s(t) = 100 lb when

t = 150 ln(1750) - 150 ln(1700)

t = 150 ln(1750/1700)

t = 150 ln(35/34)

t ≈ 4.348

5 0

3 years ago

Which answer, to the correct number of significant figures, is closest to the true value of the expression: (9.1 x 104 )(1.1 x 1

DIA [1.3K]

Answer : The correct answer is, -13000 g

Explanation :

Significant figures : The figures in a number which express the value -the magnitude of a quantity to a specific degree of accuracy is known as significant digits.

The rule apply for the multiplication and division is :

The least number of significant figures in any number of the problem determines the number of significant figures in the answer.

The given expression is:

$(9.1\times 10^4)(1.1\times 10^{-5})(\log 10^{-13})(1000)g$