21. 75% of ________ peaches is 15 peaches

Unit 5. 8) Please help. Which of the two-dimensional cross sections listed below could be created by cutting a cube with a plane

inysia [295]

Answer:

The correct answers is rectangle and square.

4 0

3 years ago

Problem PageQuestion The mass of a radioactive substance follows a continuous exponential decay model, with a decay rate paramet

asambeis [7]

Answer:

t = 1.51

Step-by-step explanation:

Exponential Model

The exponential model is often used to simulate the behavior of a magnitude that either grow or decay in proportion to the existing amount of that magnitude.

The model can be expressed as

$M=M_oe^{kt}$

In this case, Mo is the initial mass of the radioactive substance and k is a constant which value is positive if the mass is growing or negative if the mass is decaying.

The value of k is not precisely given in the question, we are assuming $k=-0.2$

The model is now

$M=M_oe^{-0.2t}$

We are required to compute the time it takes the mass to reach one-half of its initial value:

$\displaystyle \frac{M_o}{2}=M_oe^{-0.2t}$

Simplifying

$\displaystyle \frac{1}{2}=e^{-0.2t}$

Taking logarithms

$\displaystyle ln\frac{1}{2}=ln(e^{-0.2t})=-0.2t$

Solving for t

$\displaystyle t=-\frac{ln\frac{1}{2}}{0.2}=1.51$

6 0

3 years ago

Hello can someone try and help me

lyudmila [28]

Answer:

f(x)=-4x+/4

let y=f(x)

y=-4x+4

interchange the role of x & y

x=-4y+4

x-4=-4y

(x-4)/-4=y

y=-(x-4)/4

f-¹(x)=-(x-4)/4

yeah you are right

4 0

3 years ago

Regina, Phil, and Joseph each wrote expressions to represent their hourly earnings for an after-school job where h represents th

Vladimir79 [104]

Answer:

Disagree

On weeks when Joseph works extra 2/3 hours more than Phil, Phil and Joseph can earn the same amount of money

Step-by-step explanation:

The given expression for the hourly earnings of Regina, Phil and Joseph are as follows;

Regina: 6.50·h + 16

Phil: 3·(2.5·H + 5)

Joseph: 7.50·h + 10

The number of hours worked = h

The hourly earnings for Phil equated to the hourly earnings of Joseph gives;

3·(2.5·H + 5) = 7.50·h + 10

Simplifying we get;

3 × 2.5·h + 3 × 5 = 7.50·h + 10

7.5·h + 15 = 7.50·h + 10

Which gives

15 = 10 + 5 = 10 which is not correct.

Therefore, when both Phil and Joseph works the same number of hours, in the week, Phil will earn 5 units more Joseph

However, we have that, where Joseph works extra 5/7.5 or 2/3 hours more than Phil, every week, they will earn the same amount of money every week.

Therefore, it is possible for Phil and Joseph to earn the same amount of money when Joseph works extra 2/3 hours more than Phil which gives;

On weeks when Joseph works extra 2/3 hours more than Phil, Phil and Joseph can earn the same amount of money.

3 0

3 years ago

21. Paul has $900 to invest in a savings account that has an annual interest rate of 1.8%, and a money market account that pays

Iteru [2.4K]

The polynomial that gives the interest earned after a year will have variables, exponents and constants that are joined by operators.

The interest earned after one year is 0.018·x

Reasons:

The amount Paul has to invest = $900

The annual interest rate from the savings account = 1.8%

The amount the money market account pays per year = 4.2 %

Required: The polynomial for the interest Paul earned by investing x dollars in the savings account.

Solution:

The interest earned is found using the compound interest formula as follows;

$\displaystyle A = \mathbf{P \cdot \left(1 + \frac{r}{n} \right)^{n \cdot t}}$

Where;

A = The amount in the account after one year

P = The original amount invested = x

r = The interest rate offered on the investment = 1.8% = 0.018

t = The time of the investment = 1 year

n = The number of times of application of the interest per period = Once per year

Which gives;

Interest = Amount earned = A - P

Therefore;

$\displaystyle Interest, \ I = \mathbf{P \cdot \left(1 + \frac{r}{n} \right)^{n \cdot t} - P}$

Plugging in the values gives;

$\displaystyle I = x \cdot \left(1 + \frac{0.018}{1} \right)^{1 \times 1} - x = x \cdot 1.018^1 - x = 1.018 \cdot x - x = 0.018 \cdot x$

The polynomial equation is therefore;

Interest, I = 0.018·x

Using the simple interest formula, we have;

$\displaystyle Interest = \mathbf{\frac{P \times r \times t}{100}}$

Which gives;

$\displaystyle Interest = \frac{x \times 1.8 \times 1}{100} = 0.018 \cdot x$

Interest earned by investing in the savings account for one year, I = 0.018·x

The polynomial representing the interest earned is I = 0.018·x

Learn more here:

brainly.com/question/11314161

4 0

2 years ago