Which of these is a rational number?

A kilometer is more than one half a mile true or false!

Orlov [11]

The answer is true.
1 Kilometer is 0.621371 miles

4 0

3 years ago

The antibiotic clarithromycin is eliminated from the body according to the formula A(t) = 500e−0.1386t, where A is the amount re

PolarNik [594]

Answer:

Time(t) = 11.61 hours (Rounded to two decimal place)

Step-by-step explanation:

Given: The antibiotic clarithromycin is eliminated from the body according to the formula:

$A(t) = 500e^{-0.1386t}$ ......[1]

where;

A - Amount remaining in the body(in milligram)

t - time in hours after the drug reaches peak concentration.

Given: Amount of drug in the body is reduced to 100 milligrams.

then,

Substitute the value of A = 100 milligrams in [1] we get;

$100= 500e^{-0.1386t}$

Divide both sides by 500 we get;

$\frac{100}{500}=\frac{ 500e^{-0.1386t}}{500}$

Simplify:

$\frac{1}{5} = e^{-0.1386t}$

Taking logarithm both sides with base e, then we have;

$\log_e (\frac{1}{5})= \log_e (e^{-0.1386t})$

$\log_e (\frac{1}{5})=-0.1386t$ [ Using $\log_e e^a =a$ ]

or

$\log_e (0.2)=-0.1386t$

$-1.6094379124341 = -0.1386t$

[using value of $\log_e (0.2) = -1.6094379124341$ ]

then;

$t = \frac{-1.6094379124341}{-0.1386}$

Simplify:

t ≈11.61 hours.

Therefore, the time 11.61 hours(Rounded two decimal place) will pass before the amount of drug in the body is reduced to 100 milligrams

6 0

3 years ago

Simplify. (x2+2x-4)+(2x-5x-3)

vladimir2022 [97]

Answer:

Step by Step Solution

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STEP

1

:

3

Simplify ——

x2

Equation at the end of step

1

:

3

((((2•(x2))-5x)-——)+2x)-3

x2

STEP

2

:

Equation at the end of step

2

:

3

(((2x2 - 5x) - ——) + 2x) - 3

x2

STEP

3

:

Rewriting the whole as an Equivalent Fraction

3.1 Subtracting a fraction from a whole

Rewrite the whole as a fraction using x2 as the denominator :

2x2 - 5x (2x2 - 5x) • x2

2x2 - 5x = ———————— = ———————————————

1 x2

Equivalent fraction : The fraction thus generated looks different but has the same value as the whole

Common denominator : The equivalent fraction and the other fraction involved in the calculation share the same denominator

STEP

4

:

Pulling out like terms

4.1 Pull out like factors :

2x2 - 5x = x • (2x - 5)

Adding fractions that have a common denominator :

4.2 Adding up the two equivalent fractions

Add the two equivalent fractions which now have a common denominator

Combine the numerators together, put the sum or difference over the common denominator then reduce to lowest terms if possible:

x • (2x-5) • x2 - (3) 2x4 - 5x3 - 3

————————————————————— = —————————————

x2 x2

Equation at the end of step

4

:

(2x4 - 5x3 - 3)

(——————————————— + 2x) - 3

x2

STEP

5

:

Rewriting the whole as an Equivalent Fraction :

5.1 Adding a whole to a fraction

Rewrite the whole as a fraction using x2 as the denominator :

2x 2x • x2

2x = —— = ———————

1 x2

Polynomial Roots Calculator :

5.2 Find roots (zeroes) of : F(x) = 2x4 - 5x3 - 3

Polynomial Roots Calculator is a set of methods aimed at finding values of x for which F(x)=0

Rational Roots Test is one of the above mentioned tools. It would only find Rational Roots that is numbers x which can be expressed as the quotient of two integers

4 0

3 years ago

Please help<br> calculate the coefficient of x^14y^4 in the expansion of (x+y)^18

stellarik [79]

..................(1x+14y)4

3 0

4 years ago

In a survey, the eye colorseye colors of respondents are identified as 11 for brown eyes commabrown eyes, 22 for blue eyes comm

mr Goodwill [35]

Answer:

The answer is ratio Level of measurement

Step-by-step explanation:

It is important that I explain the various levels of measurement. There are four levels of measurement; nominal, ordinal, interval and ratio levels of measurement.

1. Nominal Level of Measurement; The nominal scale or level of measurement simply names or categorizes responses. examples are categorizing entries into religion, gender, hair color, etc. It is the lowest scale of measurement and they do not imply ordering among the group example, in classifying hair color, there is no numerical ordering value or red being more than black.

2. Ordinal Level of Measurement; Ordinal scale allows for comparison between two subjects to the degree of which they posses the dependent variable. For example, a researcher wanting to determine the level of satisfaction of customers to a product can group the customers from most dissatisfied to most satisfied.

3. Interval Level of Measurement; here, the level of measurement are numerical and they have the same distance (degree of difference) throughout. In the interval level of measurement, there is no true zero point on the scale, but the distance between two sets of points can have the same interval, but it will be irrational to make ratio comparisons. example is the Fahrenheit scale for temperature measurement, there is no true zero point, but a temperature difference between 20° F and 30° F is the same as the difference between 50° F and 60° F.

4. Ratio Level of Measurement; This is the most detailed level of measurement, and in addition to the interval scale, there is a true zero point. Mathematical computations can be carried out on them. It can be said to be the other three levels of measurement summed up in one. For example, money can be measured on the ratio scale because there is a zero point and it is mathematically accurate to say that 20 cents is twice as much as 10 cents. In our example, the survey is on eye color which ordinarily would have been on the nominal or categorical scale of measurement, but for the fact that the number of people possessing a quality is counted, it makes it ratio, and mean value was even calculated to be 1.5. There is a possibility of having a particular group of eye color with no participant, hence the zero point.

3 0

3 years ago