Amy needs to mail a gift card to a friend. She uses 47-cent stamps and 6-cent stamps to pay $2.42 in postage. How many of each stamp did Amy use?

Answer:

-1/4

Step-by-step explanation:

f(x) = 1/(x+1)

f(a) = 1/(a+1)

f'(a) = {(a+1)×d/da (1) - d/da (a+1) × 1}/(a+1)²

f'(a) = {(a+1)×0 - 1×1}/(a+1)²

f'(a) = (0-1)/(a²+2a+1)

f'(a) = -1/(1+2a+a²)

putting a = 1

f'(a) = -1/(1+2+1)

f'(a) = -1/4

Answer:

i) 154m

ii) 495m^2

Step-by-step explanation:

2 layers around the garden = 2*perimeter = 2(10+20+12+35) = 2(77) = 154

shape is a trapezium, area = h(a+b)/2 = 18(20+35)/2 = 495

By Green's theorem, the line integral

[tex]\displaystyle \int_C f(x,y)\,\mathrm dx + g(x,y)\,\mathrm dy[/tex]

is equivalent to the double integral

[tex]\displaystyle \iint_D \frac{\partial g}{\partial x} - \frac{\partial f}{\partial y} \,\mathrm dx\,\mathrm dy[/tex]

where D is the region bounded by the curve C, provided that this integrand has no singularities anywhere within D or on its boundary.

It's a bit difficult to make out what your integral should say, but I'd hazard a guess of

[tex]\displaystyle \int_C \left(3y+5e^{-x}\right)\,\mathrm dx + \left(10x+3\cos\left(y^2\right)\right)\,\mathrm dy[/tex]

Then the region D is

D = {(x, y) : 0 ≤ x ≤ 1 and x ² ≤ y ≤ √x}

so the line integral is equal to

[tex]\displaystyle \int_0^1\int_{x^2}^{\sqrt x} \frac{\partial\left(10x+3\cos\left(y^2\right)\right)}{\partial x} - \frac{\partial\left(3y+5e^{-x}\right)}{\partial y}\,\mathrm dy\,\mathrm dx \\\\ = \int_0^1 \int_{x^2}^{\sqrt x} (10-3)\,\mathrm dy\,\mathrm dx \\\\ = 7\int_0^1 \int_{x^2}^{\sqrt x} \mathrm dy\,\mathrm dx[/tex]

which in this case is 7 times the area of D.

The remaining integral is trivial:

[tex]\displaystyle 7\int_0^1\int_{x^2}^{\sqrt x}\mathrm dy\,\mathrm dx = 7\int_0^1y\bigg|_{y=x^2}^{y=\sqrt x}\,\mathrm dx \\\\ = 7 \int_0^1\left(\sqrt x-x^2\right)\,\mathrm dx \\\\ = 7 \left(\frac23x^{3/2}-\frac13x^3\right)\bigg|_{x=0}^{x=1} = 7\left(\frac23-\frac13\right) = \boxed{\frac73}[/tex]

The probability of selecting 2 Snickers is 3/190. The probability of selecting a Snickers and Hershey Bar in that order is 3/76. The probability of selecting a Milky Way and a Kit Kat bar in that order is 18/190.

Number of Snickers = 3

Number of Hershey Bars = 5

Number of Kit-Kat Bars = 6

Number of Milky Ways = 6

Total number of chocolates = 20

a) What is the probability of selecting 2 Snickers?

= 3/20 × 2/19

= 3/190

The probability of selecting 2 Snickers is 3/190

b) What is the probability of selecting a Snickers and Hershey Bar in that order?

= 3/20 × 5/19

= 3/76

The answer is 3/76

c) What is the probability of selecting a Milky Way and a Kit Kat bar in that order

= 6/20 × 6/19

= 18/190

The probability is 18/190

Read related link on:

https://brainly.com/question/13604758

Answer:NONE

Step-by-step explanation:

No question asked

Answer:

Test statistic = 1.664

Step-by-step explanation:

The hypothesis :

H0 : μ = 47.2

H1 : μ ≠ 47.2

Given that :

Sample mean, xbar = 47

Sample size, n = 250

Standard deviation, σ = 1.9

The test statistic :

(xbar - μ) ÷ (σ/√(n))

T = (47 - 47.2) ÷ (1.9/√(250))

T = (0.2 / 0.1201665)

Test statistic = 1.664

Answer for this prob

Answer:

Mid- point =(-4+2/2, -2+8/2)

=(-2/2,6/2)

=(-1,3)

The mid point of the line segment joining  (–4, –2) and (2,8) is (-1, 3)

mid point = (x₁ + x₂ / 2, y₁ + y₂ / 2)

Therefore,

(-4, -2)(2, 8)

x₁= -4

x₂ = 2

y₁ = -2

y₂ = 8

Hence,

mid point = (-4 + 2 / 2, -2 + 8 / 2)

mid point = (-2 / 2, 6 / 2)

mid point = (-1, 3)

learn more on mid point here: https://brainly.com/question/1501820

Answer:

speaking giberish

Step-by-step explanation:

cos it is just a word that is rare

Answer:

AA

Step-by-step explanation:

We know that all three angles are similar  as shown by the markings

I would use  AA, or the Angle Angle theorem

Answer:

50 weeks.

Step-by-step explanation:

Did the math like u should've

Formula-

If a set has “n” elements, then the number of subset of the given set is 2n and the number of proper subsets of the given subset is given by 2n-1. Consider an example, If set A has the elements, A = {a, b}, then the proper subset of the given subset are { }, {a}, and {b}

Symbol that can be used-

The symbol "⊆" means "is a subset of". The symbol "⊂" means "is a proper subset of".

Hope it helps you... pls mark brainliest if it helped you.

Answer:

c = 3.00 + .50b

Step-by-step explanation:

The cost is the flat fee plus the cost per book times the number of books

c = 3.00 + .50b

let number of green balls= x

let number of orange balls=x+4

x+x+4=38

2x=38-4

2x=34

x=17

number of green balls=17

number of orange balls=21

Answer:

$240

Step-by-step explanation:

A year has 12 month in it so lets multiply the 10 by 12 which is $120,Mean a year is $120 so 2years will be $120×2 which is $240

Answer:

x+1/5x

Step-by-step explanation:

Because the eqaution would be x+10%=x+1/10+10%=1/5+x

Then the equation equals x+1/5

Answer:

a^2 - b^2 = (a-b)(a+b)

Step-by-step explanation:

x^2 -9

Rewriting as

x^2 - 3^2

We notice that this is the difference of squares

a^2 - b^2 = (a-b)(a+b)

x^2 - 3^2 = (x-3)(x+3)

Answer:

1

Use the quadratic formula

=

−

±

2

−

4

√

2

x=\frac{-{\color{#e8710a}{b}} \pm \sqrt{{\color{#e8710a}{b}}^{2}-4{\color{#c92786}{a}}{\color{#129eaf}{c}}}}{2{\color{#c92786}{a}}}

x=2a−b±b2−4ac​​

Once in standard form, identify a, b, and c from the original equation and plug them into the quadratic formula.

2

+

5

−

2

=

0

x^{2}+5x-2=0

x2+5x−2=0

=

1

a={\color{#c92786}{1}}

a=1

=

5

b={\color{#e8710a}{5}}

b=5

=

−

2

c={\color{#129eaf}{-2}}

c=−2

=

−

5

±

5

2

−

4

⋅

1

(

−

2

)

√

2

⋅

1

Step-by-step explanation:

this should help

When you evaluate [tex]3(\frac{4}{5})[/tex] you will have [tex]\frac{12}{5}[/tex]

In this exercise, you're required to evaluate the given whole number and fraction [tex]3(\frac{4}{5})[/tex]

First of all, you will notice that there is a bracket which signifies multiplication. Therefore, we would open up the bracket by multiplying the two numbers.

Opening the bracket;

[tex]3 * \frac{4}{5}[/tex]

Multiplying the whole number by the numerator;

[tex]3(\frac{4}{5}) = \frac{12}{5}[/tex]

Find more information on how to evaluate mathematical expressions: https://brainly.com/question/24373783

Answer:

-7x-11

Step-by-step explanation:

expand brackets

6-3x-10+8-4x=15

4-7x=15

move 15 to left side

-7x-11

Answer:

4-7x=15

Step-by-step explanation:

[tex]6 - (3x + 10) + 4(2 - x) = 15 \\ 6- 3x - 10 + 8 - 4x = 15 \\ - 7x = 15 + 10 - 8 - 6\\ - 7x = 11 \\ the \: same \: one \: is \\ 4 - 7x = 15[/tex]

Answer:

t- shirt cost £7, hat cost £3

Step-by-step explanation:

let t represent cost of t- shirt and h represent cost of hat , then

4t + h = 31  → (1)

2t + h = 17 → (2)

Subtract (2) from (1) term by term to eliminate h

(4t - 2t) + (h - h) = 31 - 17 , that is

2t = 14 ( divide both sides by 2 )

t = 7

Substitute t = 7 into either of the 2 equations and solve for h

Substituting into (1)

4(7) + h = 31

28 + h = 31 ( subtract 28 from both sides )

h = 3

t- shirt cost £7 and hat cost £3

Answer:

$38427

Step-by-step explanation:

Surface Area Formula: A=2(wl+hl+hw) where l=length w=width h=height

A=2((20(22))+(22(2))+(20(2)) = 1048ft^2

3 ft = 1yds -> 1048 ft = 349 1/3 yds

349 1/3(110)= 38426.66666

$38427

Answer: $2,613,600

Step-by-step explanation:

Concept:

Here, we need to know the idea of unit conversion and a rectangular prism.

When there are multiple units occurring in the same question, then we should convert all the units into one by different conversion factors.

A rectangular prism is a three-dimensional figure that has 6 sides that are rectangles.

1 foot = 12 inches

1 yard = 3 feet

V (rectangular prism) = w · l · h

Solve:

24 inches = 24 / 12 = 2 feet

$110 per cubic yard = 110 × 3³ = $2970 per cubic feet

V = w · l · h

V = (20) (22) (2)

V = 880 feet³

880 × 2970 = $2,613,600

Hope this helps!! :)

Please let me know if you have any questions

Answer:

11.60

Step-by-step explanation:

To find unit rate, you need to use the formula:

(amount of money) ÷ (amount of hours)

Since we have both, we can plug in

140 ÷ 12 will give you approximately 11.6

So, you receive $11.60 every hour.

Answer:

Hello

Step-by-step explanation:

955÷35

27.2857142857

Or

35/955

35)955(27

-945

________

10

I hope this works♥️

Answer:

A=13×13

=169sqr.units

Answer:

MD = 2

SS = 18

SAMPLE VARIANCE = 2.25

STANDARD ERROR = 0.5

Step-by-step explanation:

Given :

A 8 7

B 7 5

C 6 6

D 7 6

E 9 7

F 8 5

G 5 4

H 9 4

I 7 4

Difference, d = Before - After

______ d

A 8 7 __ 1

B 7 5 __ 2

C 6 6 __ 0

D 7 6 __ 1

E 9 7 __ 2

F 8 5 __ 3

G 5 4 __ 1

H 9 4 __5

I 7 4 ___3

The mean of difference, MD ;

MD = Σd/ n = (1+2+0+1+2+3+1+5+3) / 9 = 18 / 9 = 2

The sum of square, SS ;

(1 - 2)^2 + (2 - 2)^2 + (0 - 2)^2 + (1 - 2)^2 + (2 - 2)^2 + (3 - 2)^2 + (1 - 2)^2 + (5 - 2)^2 + (3 - 2)^2 = 18

Sample variance, S² = SS/(N-1) = 18 / (9 - 1) = 18 / 8 = 2.25

Sample standard deviation, S = √Variance = √2.25 = 1.5

Standard Error, S.E = S / √n = 1.5 / √9 = 0.5

Test statistic : MD / S.E = 2 / 0.5 = 4

We test at α = 0.05 since no α - value is stated in the question.

Critical value at 0.05, df = 8 ;

Critical value = 2.306

Since; Test statistic > Critical value, then result is significant at α = 0.05

Answer:

what three options bro where are the options

Answer:

9 hours, 11 hours, 19 hours.

Answer:

A sample of 1699 would be required.

Step-by-step explanation:

We have that to find our [tex]\alpha[/tex] level, that is the subtraction of 1 by the confidence interval divided by 2. So:

[tex]\alpha = \frac{1 - 0.95}{2} = 0.025[/tex]

Now, we have to find z in the Z-table as such z has a p-value of [tex]1 - \alpha[/tex].

That is z with a pvalue of [tex]1 - 0.025 = 0.975[/tex], so Z = 1.96.

Now, find the margin of error M as such

[tex]M = z\frac{\sigma}{\sqrt{n}}[/tex]

In which [tex]\sigma[/tex] is the standard deviation of the population and n is the size of the sample.

Standard deviation is known to be $8.2.

This means that [tex]\sigma = 8.2[/tex]

How large of a sample would be required in order to estimate the mean per capita income at the 95% level of confidence with an error of at most $0.39?

This is n for which M = 0.39. So

[tex]M = z\frac{\sigma}{\sqrt{n}}[/tex]

[tex]0.39 = 1.96\frac{8.2}{\sqrt{n}}[/tex]

[tex]0.39\sqrt{n} = 1.96*8.2[/tex]

[tex]\sqrt{n} = \frac{1.96*8.2}{0.39}[/tex]

[tex](\sqrt{n})^2 = (\frac{1.96*8.2}{0.39})^2[/tex]

[tex]n = 1698.3[/tex]

Rounding up:

A sample of 1699 would be required.