Ask question

Ask question

All categories

AleksandrR [38]

3 years ago

5

Lucy si thinking of a Numbers. The number is greater than two hundred twenty-five. Her number is less than 2 hundreds,2 tens, an

d 7 ones. What is Lucy's number?

1 answer:

VikaD [51]3 years ago

8 0

226 i believe, if not then idk

You might be interested in

A chemical substance has a decay rate of 6.9% per day. The rate of change of an amount N of the chemical is given by the equatio

GaryK [48]

Answer:

a) $N=N_0e^{-0.069t}$

b) $N=696.9$ grams

c) $t=10$ days

Step-by-step explanation:

a)

We are going to use separation of variables to solve.

Get all your t's to one side and your N's to opposing side.

$\frac{dN}{dt}=-0.069N$

Multiply both sides by $dt$ :

$dN=-0.069N dt$

Divided both sides by $N$ :

$\frac{dN}{N}=-0.069 dt$

Integrate both sides:

$\ln|N|=-0.069t+C$

The equivalent exponential form is:

$e^{-0.069t+C}=N$

Using law of exponents you can write this as:

$e^{-0.069t}e^C=N$

$e^C$ is just a positive constant that I'm going to replace with K:

$e^{-0.069t}K=N$

Applying the symmetric property of equality:

$N=e^{-0.069t}K$

Applying the commutative property of multiplication:

$N=Ke^{-0.069t}$

K actually represents the initial amount of chemical substance since when plugging in 0 for t you get K for N, like so:

$N=Ke^{-0.069 \cdot 0}$

$N=Ke^{0}$

$N=K(1)$

$N=K$

We are given at time 0 the amount of chemical substance,N, is K. They want us to represent this value with $N_0$ instead. So the exponential equation is:

$N=N_0e^{-0.069t}$

b)

We are given $N_0=800$ at $t=0$ .

We are asked to find how much of the chemical substance, N, remains after 2 days. So we replace t with 2 in $N=800e^{-0.069t}$ :

$N=800e^{-0.069 \cdot 2}$

Put into calculator:

$N=696.9$ (this was rounded to the nearest tenths)

c)

The last part is asking for how many days will it take a initial 800 grams to go down to half of 800 grams.

We need to see the following equation:

$\frac{1}{2}(800)=800e^{-0.069t}$

$400=800e^{-0.069t}$

Divide both sides by 800:

$\frac{400}{800}=e^{-0.069t}$

Reduce the fraction:

$\frac{1}{2}=e^{-0.069t}$

Convert to logarithmic form:

$\ln(\frac{1}{2})=-0.069t$

Divide both sides by -0.069:

$\frac{\ln(\frac{1}{2})}{-0.069}=t$

Input into calculator:

$10.0=t$

$t=10.0$

$t=10$

6 0

3 years ago

Gavin spent $35.45 on four pairs Jeans each pair of Jean cost the same amount. Gavin wanted to find the price for each pair of j

Ksivusya [100]

Answer:

Each pair costs $8.86

Step-by-step explanation:

Divide 35.45 by 4

You get 8.8625

Round that to the nearest hundredth.

You get $8.86

Hope this helped!

7 0

3 years ago

PLEASE HELP GEOMETRY!! WILL GIVE BRAIN!! SHOW WORK

meriva

The Answer: 72
You add!

6 0

3 years ago

Simplify the expression 5+6i/4+6i<br> A) 56-6i/-20<br> B) -16-6i/-20<br> C)56-6i/52<br> D) -16-6i/52

IRISSAK [1]

Answer:

$The\ simplified\ form\ of\ the\ \frac{5 + 6i}{4 + 6i}\ is\ \frac{56-6i}{52}.$

Option (C) is correct .

Step-by-step explanation:

As the expression given in the question as follows.

$= \frac{5 + 6i}{4 + 6i}$

Now rationalize the expression.

$= \frac{5 + 6i\times 4 - 6i}{4 + 6i\times 4 - 6i}$

Using the formula

a² - b² = (a - b) (a + b)

Using in the above

$= \frac{5 + 6i\times 4 - 6i}{(4)^{2} - (6i)^{2}}$

$= \frac{5\times 4-5\times 6i+6i\times 4-36\ i^{2}}{16 - 36(i)^{2}}$

As i² = -1

$= \frac{20-30i+24i+36}{16 + 36}$

$= \frac{56-6i}{52}$

$Therefore\ the\ simplified\ form\ of\ the\ \frac{5 + 6i}{4 + 6i}\ is\ \frac{56-6i}{52}.$

Option (C) is correct .

8 0

3 years ago

Read 2 more answers

Patrick made a scale drawing of a newly planted hotel the height of the scale drawing is 27 inches what would be the actual heig

andrew11 [14]

Answer:

270 meters

just multiply by 10 and change metrics to scale here

7 0

3 years ago