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3 years ago

The average of m, n, and -1 is 0. What is the value of m+n?

Mathematics

1 answer:

Oxana [17]3 years ago

5 0

Answer: 1

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Explanation:

To average a bunch of numbers, we add them up and divide by how many numbers there are. In this case, we'll divide by 3 since there are 3 numbers.

Add up the values: m+n+(-1) = m+n-1

Divide by 3: (m+n-1)/3

Set this equal to 0 since we're told the average is 0: (m+n-1)/3 = 0

Now let's isolate m+n. It might help to replace "m+n" with another variable, say P to get (P-1)/3 = 0.

Solve for P

(P-1)/3 = 0

P-1 = 3*0 .... multiply both sides by 3

P-1 = 0

P = 1 ... add 1 to both sides

m+n = 1 .... replace P with m+n

So that's why the answer is 1

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Solve for x and y: x=5−2y 6y=10−3x

Mama L [17]

we have

x=5−2y ---> multiply by 3 both sides-----> 3x=15-6y-----> 6y=15-3x----> equation 1

6y=10−3x------> equation 2

equation 1 and equation 2 has the same slope

the lines are parallel

slope m=-3/6-----> m=-1/2

there are no solution

the answer is the option

b. There is no solution

7 0

4 years ago

The maximum value of 12 sin 0-9 sin²0 is: -

jeka57 [31]

Answer:

Step-by-step explanation:

The question is not clear. You have indicated the original function as 12sin(0) - 9sin²(0)

If so, the solution is trivial. At 0, sin(0) is 0 so the solution is 0

However, I will assume you meant the angle to be $\theta$ rather than 0 which makes sense and proceed accordingly

We can find the maximum or minimum of any function by finding the first derivate and setting it equal to 0

The original function is

$f(\theta) = 12sin(\theta) - 9 sin^2(\theta)$

Taking the first derivative of this with respect to $\theta$ and setting it equal to 0 lets us solve for the maximum (or minimum) value

The first derivative of $f(\theta)$ w.r.t $\theta$ is

$12\cos\left(\theta\right)-18\cos\left(\theta\right)\sin\left(\theta\right)$

And setting this = 0 gives

$12\cos\left(\theta\right)-18\cos\left(\theta\right)\sin\left(\theta\right) = 0$

Eliminating $cos(\theta)$ on both sides and solving for $sin(\theta)$ gives us

$sin(\theta) = \frac{12}{18} = \frac{2}{3}$

Plugging this value of $sin(\theta)$ into the original equation gives us

$12(\frac{2}{3}) - 9(\frac{4}{9} ) = 8 - 4 = 4$

This is the maximum value that the function can acquire. The attached graph shows this as correct

3 0

2 years ago

Patrick has just finished building a pen for his new dog. The pen is 3 feet wider than it is long. He also built a doghouse to p

zalisa [80]

General Idea:

(i) Assign variable for the unknown that we need to find

(ii) Sketch a diagram to help us visualize the problem

(iii) Write the mathematical equation representing the description given.

(iv) Solve the equation by substitution method. Solving means finding the values of the variables which will make both the equation TRUE

Applying the concept:

Given: x represents the length of the pen and y represents the area of the doghouse

Statement 1: "The pen is 3 feet wider than it is long"

$Length \; of\; the \; pen = x\\ Width \; of\; the\; pen=x+3$

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Statement 2: "He also built a doghouse to put in the pen which has a perimeter that is equal to the area of its base"

$Area \; of\; the\; Dog \; house=y\\ Perimeter \; of\; Dog\; house=y$

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Statement 3: "After putting the doghouse in the pen, he calculates that the dog will have 178 square feet of space to run around inside the pen."

$Area \; of \; the\; Pen - Area \;of \;the\;Dog \;House=\;Space\;inside\;Pen\\ \\ x \cdot (x+3)-y=178\\ Distributing \;x\;in\;the\;left\;side\;of\;the\;equation\\ \\ x^2+3x-y=178\Rightarrow\; 1^{st}\; Equation\\$

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Statement 4: "The perimeter of the pen is 3 times greater than the perimeter of the doghouse."

$Perimeter\; of\; the\; Pen=3\; \cdot \; Perimeter\; of\; the\; Dog\; House\\ \\ 2(x \; + \; x+3)=3 \cdot y\\ Combine\; like\; terms\; inside\; the\; parenthesis\\ \\ 2(2x+3)=3y\\ Distribute\; 2\; in\; the\; left\; side\; of\; the\; equation\\ \\ 4x+6=3y\\ Subtract \; 6\; and \; 3y\; on\; both\; sides\; of\; the\; equation\\ \\ 4x+6-3y-6=3y-3y-6\\ Combine\; like\; terms\\ \\ 4x-3y=-6 \Rightarrow \; \; 2^{nd}\; Equation\\$