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guajiro [1.7K]
3 years ago
9

-3|r+4|=-21 need help for a friend

Mathematics
1 answer:
KonstantinChe [14]3 years ago
4 0
Ans given below

-3r-12=-21
-3r=-21+12
-3r=-9
r=-9\-3
r=3
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I need help understanding a solution
ryzh [129]

Answer:

What they mean is if you substitute the value given for x into the equation given, is the math statement true.

Step-by-step explanation:

1) Is x = -3 a solution to 6x + 4 = -12?

6(-3) + 4 = -18 + 4 = - 14, so no, for number 1, x = -3 is not a solution to 6x + 4 = -12

Make sense?

LMK if you need me to run the rest of them with you.

8 0
3 years ago
Read 2 more answers
The point (8,1) is on the line. (Remember the line continues in both directions forever.)
Scorpion4ik [409]

the answear us true im preety sure

6 0
3 years ago
the school newspaper has a circulation of 500 and sells for $.035 a copy. the students decide to raise the price to increase the
Alik [6]

Let x be the number of times they raise the price on the newspaper. Then the new cost of the newspaper is

.35+.05x

Let y be the newspaper they sell, then the income will be

y(.35+.05x)

Now, we know that the circulation is of 500, assuming that they sold every newspaper at the original price now the number the will sell will be

y=500-20x

Plugging the value of y in the first expression we have that the income will be

\begin{gathered} f(x)=(500-20x)(.35+\text{0}.5x)=175+25x-7x-x^2 \\ =-x^2+18x+175 \end{gathered}

Then the income is given by the function

f(x)=-x^2+18x+175

To find the maximum value of this functions (thus the maximum income) we need to take the derivative of the function,

\begin{gathered} \frac{df}{dx}=\frac{d}{dx}(-x^2+18x+175) \\ =-2x+18 \end{gathered}

no we equate the derivative to zero and solve for x.

\begin{gathered} \frac{df}{dx}=0 \\ -2x+18=0 \\ -2x=-18 \\ x=\frac{-18}{-2} \\ x=9 \end{gathered}

This means that we have an extreme value of the function when x=9. Now we need to find out if this value is a maximum or a minimum. To do this we need to take the second derivative of the function, then

\begin{gathered} \frac{d^2f}{dx^2}=\frac{d}{dx}(\frac{df}{dx}) \\ =\frac{d}{dx}(-2x+18) \\ =-2 \end{gathered}

Since the second derivative is negative in the point x=9, we conclude that this value is a maximum of the function.

With this we conclude that the number of times that they should raise the price to maximize the income is 9. This means that they will raise the price of the newspaper (9)($0.05)=$0.45.

Therefore the price to maximize the income is $0.35+$0.45=$0.80.

4 0
1 year ago
What is the equation of the line that passes through the point (-2, 7) and has a slope of zero
lorasvet [3.4K]

Answer:

y = 7 is the equation of the line that passes through the point ( -2, 7 ) and has a slope of zero.

Step-by-step explanation:

Given:

Let,

A ≡ ( x1 , y1 ) ≡ ( -2, 7 )

Slope = m = 0

To Find :

Equation of Line:

Solution:

Formula for , equation of a line passing through a point (  x1 , y1 ) and having a slope m is given by

(y - y_{1})=m(x-x_{1})

Now substituting the values of x1 = -2 and y1 = 7 and slope m = 0 we get,

y-7=0\times(x--2) \\y-7=0\times (x+2)\\y-7=0\\\therefore y=7

Which is the required equation of a line passing through the point ( -2, 7 ) and slope zero

6 0
3 years ago
20×+4=4(5x+1) how many solution are in this equation
Tomtit [17]

Simplify both sides of the equation

(20)(4)= 4(5x+1)

Simplify

80 = 20x+4

Flip the equation

20x+4 = 80

Subtract 4 from both sides

20x+4-4 = 80-4

20x = 76

Divide both sides by 20

20x/20 = 76/20

x= 3.8


There is one solution in this equation

7 0
3 years ago
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