A road is 450 metres long . It takes a woman 5 minutes to walk along the road . Work out the average speed of the woman . Give your answer in metres per second .​

The differential equation

[tex]M(x,y) \, dx + N(x,y) \, dy = 0[/tex]

is considered exact if [tex]M_y = N_x[/tex] (where subscripts denote partial derivatives). If it is exact, then its general solution is an implicit function [tex]f(x,y)=C[/tex] such that [tex]f_x=M[/tex] and [tex]f_y=N[/tex].

We have

[tex]M = \tan(x) - \sin(x) \sin(y) \implies M_y = -\sin(x) \cos(y)[/tex]

[tex]N = \cos(x) \cos(y) \implies N_x = -\sin(x) \cos(y)[/tex]

and [tex]M_y=N_x[/tex], so the equation is indeed exact.

Now, the solution [tex]f[/tex] satisfies

[tex]f_x = \tan(x) - \sin(x) \sin(y)[/tex]

Integrating with respect to [tex]x[/tex], we get

[tex]\displaystyle \int f_x \, dx = \int (\tan(x) - \sin(x) \sin(y)) \, dx[/tex]

[tex]\implies f(x,y) = -\ln|\cos(x)| + \cos(x) \sin(y) + g(y)[/tex]

and differentiating with respect to [tex]y[/tex], we get

[tex]f_y = \cos(x) \cos(y) = \cos(x) \cos(y) + \dfrac{dg}{dy}[/tex]

[tex]\implies \dfrac{dg}{dy} = 0 \implies g(y) = C[/tex]

Then the general solution to the exact equation is

[tex]f(x,y) = \boxed{-\ln|\cos(x)| + \cos(x) \sin(y) = C}[/tex]

The value of x will be 158. The value of x is obtained by simplifying the equation.

A mathematical statement consisting of an equal symbol between two algebraic expressions with the same value is known as an equation.

Identity used;

(x+a)(x-a) = x² - a²

Given expression;

3(x-7)(x+7) - (x-1)(3x+2) = 13

Solving the equation step by step;

[tex]\rm 3(x^2 - 7^2 ) - [x(3x+2)-1(3x+2) ]= 13\\\\ 3x^ 2 -147 -[3x^2 +2x -3x-2] = 13 \\\\ 3x^2 -147 -[3x^2 -x-2] = 13\\\\ 3x^2-147-3x^2 +x+2 = 13 \\\\ x= 13+145 \\\\ x= 158[/tex]

Hence, the value of x will be 158.

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Answer:

all 50 states

Step-by-step explanation:

The equation is [tex]f(t)=50(0.5)^{\frac {10}{5.3}}[/tex] and approximately 13.52  milligram remains

The missing information in the question is:

[tex]f(t)=m(0.5)^{\frac th}[/tex]

When the mass is 50 mg, it means that:

m = 50

So, we have:

[tex]f(t)=50(0.5)^{\frac th}[/tex]

When 10 years remain in the life of the substance, it means that:

t = 10

So, we have:

[tex]f(t)=50(0.5)^{\frac {10}h}[/tex]

The half life is 5.3. So, we have

[tex]f(t)=50(0.5)^{\frac {10}{5.3}}[/tex]

Evaluate the equation

f(t) = 13.52

Hence, the required equation is [tex]f(t)=50(0.5)^{\frac {10}{5.3}}[/tex] and approximately 13.52  milligram remains

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Answer:c

Step-by-step explanation:

Answer:

7

Step-by-step explanation:

You were correct in setting the equation equal to 0 because the problem is asking for when the rock hits the ground and in this problem, you may  assume that the ground is y=0, unless the problem says otherwise.

Ok so where you went wrong is that when you factored out and got

(x-7)(x+2), which is correct, you forgot to set these equal to zero (because your actual equation is set to zero). So you should have

x-7 = 0

and

x+2 = 0

and this gives the actual answers +7 and -2. And since time cant be negative its 7 seconds.

This was a silly mistake and happens a lot more often than you think, so I wouldn't worry too much but make sure you practice more, better to lose points on harder questions than easy ones.

Good luck with your exam !

Answer:

7 seconds

Step-by-step explanation:

Given function:

[tex]y=-2x^2+10x+28[/tex]

where:

To find the time when the rock hits the ground, set the equation to zero and solve for x.

First, simplify by factoring out the common term  -2:

[tex]\implies -2(x^2-5x-14)=0[/tex]

Divide both sides by -2:

[tex]\implies x^2-5x-14=0[/tex]

To factor a quadratic in the form [tex]ax^2+bx+c[/tex], find two numbers that multiply to ac and sum to b.

[tex]\implies ac=1 \cdot -14=-14[/tex]

[tex]\implies b=-5[/tex]

Therefore, the two numbers that multiply to -14 and sum to -5 are: -7 and 2

Rewrite b as the sum of these two numbers:

[tex]\implies x^2-7x+2x-14=0[/tex]

Factorize the first two terms and the last two terms separately:

[tex]\implies x(x-7)+2(x-7)=0[/tex]

Factor out the common term (x - 7):

[tex]\implies (x+2)(x-7)=0[/tex]

Therefore:

[tex]\implies x+2=0 \implies x=-2[/tex]

[tex]\implies x-7=0 \implies x=7[/tex]

As time cannot be negative, the rock hits the ground in 7 seconds.

Step-by-step explanation:

here is your answer. where are you from

The cost price is Rs22600, the marked price is Rs31640 and the Profit percentage is 19%.

The percentage is defined as a given amount in every hundred. It is a fraction with 100 as the denominator percentage is represented by the one symbol %.

For example, if you say 678, we must also know the whole number, but if you say 80%, it becomes evident. The percentage is the same as the amount of that value but ranges from 1 to 100.

Let's say

Cost of article = c

Given,

Marked 40% above the cost price and sold with 15% discount including 10% VAT at Rs. 26,894

1.4c - 0.15×(1.4c) = 26894

c = Rs 22600

So,

Marked price = 1.40c = Rs 31640

Profit percentage = ( 26894 - 22600)22600 = 19%.

Hence cost price is Rs22600, the marked price is Rs31640 and the Profit percentage is 19%.

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The completed table is given below,

the percentage of girls in the class is 47.62%,

the percentage of boys in the class is (100-47.62)% = 52.38%,

the percentage of students that love Math is 36.5%,

the percentage of students that love Reading is 22%, and

the percentage of students that love Science is 41.27%

To make comparison and statistical analysis easier, numerical data is systematically and logically represented in tabulations as rows and columns. Grouping relevant data together makes comparison easier and aids in statistical analysis and interpretation.

To put it another way, tabulation is the process of organizing data and presenting it in a tabular format. Depending on the type of categorization, it might be double, complicated, or simple.

The below table yields that

The total number of students is 315

The fraction of girls in the class is 150/315 = 0.4762

So, the percentage of girls in the class is 47.62%

Hence the percentage of boys in the class is (100-47.62)% = 52.38%

The fraction of students that love Math is 115/315 = 0.365

So, the percentage of students that love Math is 36.5%

The fraction of students that love Reading is 70/315 = 0.22

So, the percentage of students that love Reading is 22%

The fraction of students that love Science is 130/315 = 0.4127

So, the percentage of students that love Science is 41.27%

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Using it's concept, it is found that the inverse function is [tex]y = \sqrt{9 - x}[/tex], and the domain is [tex]x \leq 9[/tex].

The inverse of a function y = f(x) is found exchanging x and y and isolating y. The domain of the inverse is the range of the original function f(x).

In this problem, the function is:

y = 9 - x²

Then, we exchange and isolate y, hence:

[tex]x = 9 - y^2[/tex]

[tex]y² = 9 - x[/tex]

[tex]y = \sqrt{9 - x}[/tex]

The domain is [tex]9 - x \geq 0 \rightarrow x \leq 9[/tex], as looking at the graph of y = 9 - x², the range is [tex]y \leq 9[/tex].

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Answer:

let the original price be X

now new price = original price + increment

increment = 5 % of X = X/20

new price = 194.25

now, 194.25 = X + X / 20 = 21X / 20

X = 194.25 * 20 / 21

X = 185

original price = 185

Answer:

20.4 years (nearest tenth)

Step-by-step explanation:

Compound Interest Formula

[tex]\large \text{$ \sf A=P\left(1+\frac{r}{n}\right)^{nt} $}[/tex]

where:

Given:

Substitute the given values into the formula and solve for t:

[tex]\implies \sf 15000=6000\left(1+\frac{0.045}{12}\right)^{12t}[/tex]

[tex]\implies \sf \dfrac{15000}{6000}=\left(1.00375\right)^{12t}[/tex]

[tex]\implies \sf 2.5=\left(1.00375\right)^{12t}[/tex]

[tex]\implies \sf \ln (2.5)=\ln \left(1.00375\right)^{12t}[/tex]

[tex]\implies \sf \ln (2.5)=12t \ln \left(1.00375\right)[/tex]

[tex]\implies \sf t=\dfrac{\ln (2.5)}{12 \ln (1.00375)}[/tex]

[tex]\implies \sf t=20.40017123[/tex]

Therefore, it would take 20.4 years (nearest tenth) for the investment to reach $15,000.

Answer:

The height of the balloon at 09 18 =  788.4 meters.

Step-by-step explanation:

As the hot air balloon is descending.

and the height of the balloon n minutes after it starts to descend is [tex]h_{n}[/tex]

meters.

The height of the balloon (n +1) minutes after it starts to descend, [tex]h_{n+1}[/tex]meters, is given by

[tex]h_{n+1}[/tex]= [tex]k *h_{n}+20\\[/tex] where K is a constant

Here the balloon starts to descend from a height of 1200 meters at 09 15

So [tex]h_{n}[/tex]=1200 meters

At 09 16 the height of the balloon is 1040 meters.

So  [tex]h_{n+1}[/tex]= 1040 meters

the height of the balloon at 09 18 = [tex]h_{n+3}[/tex] meters

now  [tex]h_{n+1}[/tex]= [tex]k *h_{n}+20\\[/tex]

k = [tex]\frac{h_{n+1 }-20 }{h_{n} }[/tex]

k= (1040 - 20) ÷ 1200

k = 0.85

Now [tex]h_{n+2}[/tex] = (0.85 × 1040) +20 =904 meters

Similarly  [tex]h_{n+3}[/tex] = (0.85 × 904) +20 = 788.4 meters.

Therefore the height of the balloon at 09 18 =  788.4 meters.

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Step-by-step explanation:

1. first multiply -1 times all elements of matrix A

2. then multiply 1/3 by all elements of matrix B

3. then add each corresponding entries to get the result.

from step 1. matrix A will be

-4 -2. -1. -3

-2. 0. 1. -3

step 2. matrix B will be

3. -1. -2. -4

3. -10. 10. -1

add each corresponding elements to get

-1. -3. -3. -7

1. -10 11. -4

Answer:

The answer would be 6x^2 + 5x - 4 = 0

Answer:

1 55

2 455

3554

Step-by-step explanation:

nfn

Answer:

cost of car = 34500

selling price = 29700

amount of loss = 34500 - 29700 = 4800

loss percentage = (loss amount ÷ cost price ) * 100

= 13.913 ≈ 14% loss

Answer:

i think the answer is C. 1/2

Answer:

[tex]\fbox {x = 3}[/tex]

Step-by-step explanation:

Decimal form of the lower and higher limits :

Hence, the best one which lies in the middle of the limits would be 0.3.

Now, equate the middle part :

If g(x) = 3 · x - 1 and [tex]f(x) = \sqrt{9-x^{2}}[/tex], then the domain of the division of f(x) by g(x) is equal to the following composite interval: [-3, 1/3) ∪ (1/3, 3] (Correct choice: A)

Binary operators are operators that involves two functions, there are four binary operators: (i) Addition, (ii) Subtraction, (iii) Multiplication, (iv) Division. First, we determine the domains of the functions f(x) and g(x):

f(x):

Domain - [-3, 3]

g(x):

Domain - (- ∞, + ∞)

If we divide f(x) by g(x), then we must take g(x) = 0 into account, since it leads to indetermination. In this case, x = 1/3. Then, the domain of the resulting function:

(f/g)(x):

Domain - [-3, 1/3) ∪ (1/3, 3]

If g(x) = 3 · x - 1 and [tex]f(x) = \sqrt{9-x^{2}}[/tex], then the domain of the division of f(x) by g(x) is equal to the following composite interval: [-3, 1/3) ∪ (1/3, 3] (Correct choice: A)

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The range of the relation is {0, 2, 4}

The range of the relation are the y values

From the table, we have:

y values = 0, 2, 4, 2, 0

Remove the repetition

y values = 0, 2, 4

Hence, the range of the relation is {0, 2, 4}

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Answer:

(a) 2.5

Step-by-step explanation:

(a) Since y is directly proportional to x we can write y and x in terms of the following equation:

y = cx where c is a constant
and c = y/x ...(1)
or,

x = y/c ...(2)

For (a)
y = 8 when x = 2 ==> c = y/x = 8/2 =4 from (1)

From (2) we get x = 10/4 = 2.5

The other questions can be solved in a similar fashion

Answer:

[tex] \frac{18}{12} = \frac{24}{x - 2} [/tex]

By definition of the subtraction of squares, the binomial 49 · x² - 36 have the following two factors: 7 · x + 6, 7 · x - 6 (Correct choices: C, D)

A subtraction of squares is a binomial which satisfies the following property:

a² - b² = (a - b) · (a + b)     (1)

If we know that a² = 49 · x² and b² = 36, then we have the following factors:

49 · x² - 36 = (7 · x - 6) · (7 · x + 6)

By definition of the subtraction of squares, the binomial 49 · x² - 36 have the following two factors: 7 · x + 6, 7 · x - 6 (Correct choices: C, D)

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Answer:

[tex]log\boxed{7}[/tex]

Step-by-step explanation:

Answer:

1317 is the additive inverse of x = -1317.

Step-by-step explanation:

Additive inverse of a number which when added to the original number gives zero as the result.

Additive inverse of x = -1317

-1317 + 1317 = 0

1317 is the additive inverse of x = -1317.

Verification of -(-x) = x

L. H. S

-(-x) = -{-(-1317)}

= - 1317

R. H. S

x = -1317

Thus, L.H.S. = R.H.S

-(-x) = x

Verified

Answer:

lklklkj

Step-by-step explanation:

67890-

The correct answer is option C which is 230p – 1010 = 650p – 400 – p this expression is same as of 2.3p – 10.1 = 6.5p – 4 – 0.01p.

Expression in maths is defined as the collection of the numbers variables and functions by using signs like addition, subtraction, multiplication, and division.

Given expression:-

2.3p – 10.1 = 6.5p – 4 – 0.01p

The same expression will be calculated as:-

Multiply the given expression by 100 we will get our answer.

E = 100 (s 2.3p – 10.1 = 6.5p – 4 – 0.01p )

E = 230p – 1010 = 650p – 400 – p

Therefore  the correct answer is option C which is 230p – 1010 = 650p – 400 – p this expression is same as of 2.3p – 10.1 = 6.5p – 4 – 0.01p.

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