A balanced scale has 3 marbles, 2 pennies, and 4 quarters on one side and 4 marbles, 2
quarters, and 1 penny on the other side. If pennies weigh one gram and quarters weigh
3 grams, find the weight of a marble. Explain or show your reasoning.

Answer:

The ordered pair is not a solution as both sides of the equation do not equal each other.  

Step-by-step explanation:

(3,2);  x + 6y = 13

(3) + 6(2) = 13

3 + 12 = 13

15 = 13

Answer:

  (0, ∞)

Step-by-step explanation:

The only maximum, local or otherwise, is at x=0. Since the leading coefficient is negative, the function is decreasing and concave down for x-values greater than 0.

  0 < x < ∞ . . . . . decreasing and concave down

__

Since the leading coefficient of this even-degree function is negative, it will have a generally ∩ shape. It will be decreasing to the right of any local maximum.

The first derivative is negative only for x > 0, so that is the only region where the function is decreasing. Since that x=0 is a local maximum, the function must be concave downward in that neighborhood.

__

The attached graph shows the function and its first and second derivatives. The function is concave down where the second derivative is negative, to the right of the right-most point of inflection.

_____

Additional comment

A graphing calculator provides a quick answer to a question like this. You can find the same answer algebraically.

The first derivative is ...

  f'(x) = -8x^3 -48x^2 -72x = -8x(x^2 +6x +9) = -8x(x+3)^2

This has a zero at x=-3 where the graph of it touches the x-axis, but does not change sign. That means f(x) has a flat spot at x=-3, but is not decreasing except to the right of x=0.

The second derivative is ...

  f''(x) = -24x^2 -96x -72 = -24(x^2 +4x +3) = -24(x +1)(x +3)

The second derivative will be negative for x < -3 and x > -1, to the left and right of the points of inflection. This means f(x) is concave upward only for -3 < x < -1, and concave downward everywhere else.

The function is concave downward and decreasing for x > 0.

The values of a and be for which x = 4 is a solution of the equation shown.

ax + 4 = 5x + b are infinitely many

The given equation is:

ax  +  4  =  5x   +  b

To find the values of a and b in the equation at x = 4, substitute x = 4 into the equation

4a  +  4  =  5(4)  +  b

4a  +  4   =  20  +  b

Collect like terms

4a  -  b  =  20  -  4

4a  -  b   =   16

Since there are two unknowns in just a single equation, the equation has more than 1 solution.

The values of a and be for which x = 4 is a solution of the equation shown.

ax + 4 = 5x + b are infinitely many

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Answer:

#1 and #3

Step-by-step explanation:

Area =[tex]\pi r^{2}[/tex]

The diameter is double the length of the radius

7 ÷ 2 = 3.5

3.5 × 3.5 = 12.25

[tex]12.25\pi[/tex] = 38.4845100064751

38.4845100064751 rounded to the nearest tenth is 38.5

Answer:

A = 38.5 sq meters

Step-by-step explanation:

A = πr²

since diameter is 7, then radius is 7/2

A = π(7/2)²

A = 38.48

A = 38.5 rounded to nearest tenth

Answer:

x= < 4 9/10

Step-by-step explanation:

I hope this helps

Have a great and blessed day

Answer:

K12 Answer

Step-by-step explanation:

Answer:

D

Step-by-step explanation:

The line starts at 10 so I think it's that

Answer:

Slope of a line

m = \frac{\text{rise}}{\text{run}} = \frac{y_2 - y_1}{x_2 - x_1}

m = slope

(x_1, y_1) = coordinates of first point in the line

(x_2, y_2) = coordinates of second point in the line

Step-by-step explanation:

Khan Academy

Slope review | Algebra (article) | Khan Academy

Answer: Sarah got 60 questions correct, 15 questions wrong, and she got 20% of the questions wrong.

Step-by-step explanation:

First, let's solve for how many questions Sarah got correct.

80% as a fraction can be simplified as [tex]\frac{8}{10}[/tex]. To find how many questions Sarah answered correctly, we can set up a proprtional relationship as follows:

[tex]\frac{8}{10}=\frac{?}{75}[/tex]

Next, after we cross multiply, 8 X 75 = 600, and 600 ÷ 10 = 60

So, Sarah got 60 out of 75 questions correct.

To find how many she missed, we can simply subtract 60 from 75 to get 15.

So, Sarah got 15 out of 75 questions wrong.

Finally, to find the percentage of the questions that Sarah got wrong, we can use the 15 out of 75 incorrect questions that we found earlier to create a percentage.

15 ÷ 75 = 0.2

0.2 X 100 = 20

So, Sarah got 20% of the questions wrong.

Inequalities are used to represent unequal expressions.

The inequalities are given as:

[tex]x - 99 \le -104[/tex]

[tex]x - 51 \le -43[/tex]

[tex]150 + x \le 144[/tex]

[tex]75 < 69 - x[/tex]

Start by solving for x in all the inequalities

[tex]x - 99 \le -104[/tex]

Make x the subject: Add 99 to both sides

[tex]x \le 99 - 104[/tex]

[tex]x \le -5[/tex]

[tex]x - 51 \le -43[/tex]

Make x the subject: Add 51 to both sides

[tex]x \le 51 - 43[/tex]

[tex]x \le 8[/tex]

[tex]150 + x \le 144[/tex]

Make x the subject: Subtract 150 from both sides

[tex]x \le 144 - 150[/tex]

[tex]x \le -6[/tex]

[tex]75 < 69 - x[/tex]

Make x the subject: Add x to both sides, and subtract 75 from both sides

[tex]x < 69 - 75[/tex]

[tex]x < -6[/tex]

Hence, the solutions to the inequalities are: [tex]x \le -5[/tex], [tex]x \le 8[/tex], [tex]x \le -6[/tex] and [tex]x < -6[/tex]

See attachment for the number graphs

Read more about inequalities at:

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Answer:

[tex]x=\frac{275}{62}[/tex] , [tex]y=\frac{127}{31}[/tex]

Step-by-step explanation:

We want to make the X's the same:

[tex]24x-15y=45[/tex]

[tex]24x+16y=172[/tex]

Because the signs of the X's are the same we subtract the 2 equations to make:

(I put the second one on top of the 1st)

[tex]31y=127[/tex]

So:

[tex]y=\frac{127}{31}[/tex]

Substitute y into either equation 1 or 2:

(I chose equation 1)

[tex]8x-5(\frac{127}{31})=15[/tex]

[tex]8x=5(\frac{127}{31}) + 15[/tex]

[tex]x=\frac{5(\frac{127}{31})}{8}[/tex]

So:

[tex]x=\frac{275}{62}[/tex]

don't quote me on this but I'm pretty sure it's H multiplication property of inequality

The equation showing the relationship between w and t is [tex]w = 4t[/tex]

From the table, we have the following points:

(0,0) and (1,4)

Start by calculating the slope (m)

[tex]m = \frac{y_2 -y_1}{x_2 -x_1}[/tex]

So, we have:

[tex]m = \frac{4 -0}{1 -0}[/tex]

Simplify the numerator and the denominator

[tex]m = \frac{4}{1}[/tex]

Divide 4 by 1

[tex]m = 4[/tex]

The equation is then calculated as:

[tex]w = m(t - t_1) + w_1[/tex]

This gives

[tex]w = 4(t - 0) + 0[/tex]

Simplify

[tex]w = 4t[/tex]

Hence, the equation is [tex]w = 4t[/tex]

Read more about linear equations at:

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The equation for slope intercept form is y = mx + b.

An example would be y = 3x + 4 or y = -2/5x - 4

[tex]8x - 7y = 23 \\ 8x - 23 = 7y \\y = \frac{8}{7} x - \frac{23}{7} [/tex]

The solution of the equation, when it is solved for y, has one variable term x with coefficient 8/7 and one constant term 23/7, 8/7x-23/7.

The solution of an equation is the value of the variable of the equation, for which the equation is satisfied.

To solve an equation for its variable, isolate the variable on one side of the equation using the mathematical operations.

The given expression is,

[tex]8x - 7y = 23[/tex]

The expression has two variables, x and y. To solve it for y, subtract 8x from both sides,

[tex]8x - 7y -8x= 23-8x\\-7y=23-8x[/tex]

Divide with number 7 both sides and change the sign of the equation,

[tex]y=-\left(\dfrac{23-8x}{7}\right)\\y=\dfrac{8x-23}{7}\\y=\dfrac{8}{7}x-\dfrac{23}{7}[/tex]

Thus, the solution of the equation, when it is solved for y, has one variable term x with coefficient 8/7 and one constant term 23/7, 8/7x-23/7.

Learn more about the solution of the equation here;

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Answer:

false

Step-by-step explanation:

Answer:

A rational number can be written as a fraction. Try finding the square root of 50 and see if you can rewrite it in fraction form.

Step-by-step explanation:

The reasonable estimate for the length of side DE is 3 units

Find the diagram of the question attached. The given triangle ABC and BDE are similar triangles.

Using the similarity theorem of a triangle, this is expressed as:

AC = DE

Using the pythagoras theorem to get the length of AC:

AB^2 = AC^2 + BC^2

5^2 + AC^2 + 4^2

AC^2 = 25 - 16

AC^2 = 9

AC= 3

Since AC = DE, hence the reasonable estimate for the length of side DE is 3 units

Learn more on similar shapes here: https://brainly.com/question/14285697

Answer:

5/3

Step-by-step explanation:

The approximate percentage error on the weight of the beaker is 5%

Percent error is the difference between estimated value and the actual value in comparison to the actual value and is expressed as a percentage. In other words, the percent error is the relative error multiplied by 100.

Error = Actual value - estimated value =

Actual value = 82g, Estimated value = 78g

Error = 82 - 78 which is 4

percent error = error/estimated x 100%

percent error = 4/78 x 100 which is 5%

In conclusion the percent error is 5%

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Answer:

3:55

Step-by-step explanation:

add 35 to 20 then put the hour =

3:55

Answer:

9/4 (1.75 - 21/4)

=9/4 (1.75 - 5.25)

=2.25 -3.5

= -1.25

I think your f answer is wrong

there should be -1.25

Answer:

The y = 0.5 the x = 1

Step-by-step explanation:

The y = 0.5 the x = 1

Answer:

y=1/2x

Step-by-step explanation:

y=mx+b, where m is the slope, b is the y-int and y and x are variables.

y=1/2x+0 is the answer but you dont need to add the 0.

To get the slop you do RISE/RUN which in this case is 1/2

Hope that helps. Brainliest is appreciated

Answer:

its c

Step-by-step explanation:

The best example of a down payment is given as follows:

C. Billy orders a piano, pays half the cost up front, and has to pay the other half when the piano is delivered.

The down payment of a purchase is when a part of the purchase is paid when the purchase is made, and the other part(subjected to interest or not), is paid later.

In this problem, the example of a down payment is given by option C.

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Answer:

B. Robby pays 10 percent cash up front and gets a loan for the remaining 90 percent of the cost of a condominium

Step-by-step explanation:

i just did it

Answer:the answer is b 10/21

Step-by-step explanation:

Answer:

B) 10/21

Step-by-step explanation:

Keep, change, flip

keep 2/7, change to multiply, flip to 5/3

2/7 x 5/3 = 10/21

Hope this helps! Pls give brainliest!

Answer:

5 and 15

Step-by-step explanation:

20 = 3x+x

Answer: The smallest number is 20, and the largest number is 27. (27 - 20) + 1 = 8. Eight numbers make 4 pairs, and the sum of each pair is 47. 4 x 47 = 188. The sum of the numbers from 20 to 27 is 188.

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Work Shown:

(height)/(shadow length) = (height)/(shadow length)

(5 ft)/(6.5 ft) = (x ft)/(26 ft)

5/(6.5) = x/26

5*26 = 6.5*x

130 = 6.5x

6.5x = 130

x = 130/(6.5)

x = 20

The palm tree is 20 feet tall, which is the same height as a 2 story building (assuming each floor is 10 ft).