How you express the average of five quizzes is 85 in mathematical expression​

Answer:

The answer is C.

Step-by-step explanation:

4(.032) + 3(2.458) = 7.502

7(.032) + 9(1.531) = 14.003

4(2.458) - 1.531 = 8.301

The solutions to the system of equation are x = 0.032, y = 2.458, z = 1.531 after using the inverse matrix method option (C) is correct.

It is defined as the group of numerical data, functions, and complex numbers in a specific way such that the representation array looks like a square, rectangle shape.

We have a system of equations:

4x + 3y = 7.5

7x + 9z = 14

4y - z = 8.3

First we have to write above system of equation in the form of:

AX = B

[tex]\rm X = A^{-1}B[/tex]

Where A, X and B are the matrix such that:

[tex]\rm A = \left[\begin{array}{ccc}4&3&0\\7&0&9\\0&4&-1\end{array}\right][/tex]

[tex]\rm X = \left[\begin{array}{c}x\\y\\z\end{array}\right][/tex]

[tex]\rm B = \left[\begin{array}{c}7.5\\14\\8.3\end{array}\right][/tex]

[tex]\rm \left[\begin{array}{ccc}4&3&0\\7&0&9\\0&4&-1\end{array}\right] \left[\begin{array}{c}x\\y\\z\end{array}\right] \rm = \left[\begin{array}{c}7.5\\14\\8.3\end{array}\right][/tex]

Now find the determinant of matrix A

|A| = -123

[tex]\rm A^{-1}= \dfrac{Adj(A)}{Det(A)}[/tex]

After calculating, we will get:

x = 0.032, y = 2.458, z = 1.531

Thus, the solutions to the system of equation are x = 0.032, y = 2.458, z = 1.531 after using the inverse matrix method

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Answer:

y=−1/7

for the picture is y=-57/7

Step-by-step explanation:

Switch:sides

-7y+7=8

subtract 7 from both sides

-7y=1

divide both sides by -7

y=−1/7

multiply both sides by (y+7)

8/y+7(y+7)=-7(y+7)

simplify 8=-7(y+7)

flip

-7(y+7)=8

divide both sides by -7

y+7=-8/7

subtract 7 from both sides

and simplify

y=-57/7

Answer:

The measures of the angles are 16° and 164°.

Step-by-step explanation:

Let the smaller angle be x and the larger angle be 8x+36.

Supplementary angles add up to 180°.

Small angle + Large angle = 180°

x + 8x + 36 = 180

9x + 36 = 180

9x = 180 - 36

    = 144

x = 144 ÷ 9

x = 16

8x+36 = 8(16)+36

           = 164

Answer:

x=29

Step-by-step explanation:

the degree of a straight line is 180°

180-149

=31

x+2=31

x+2-2=31-2

x=29

length (l) =54

breath (b) =72

l²+b²= diagonal²..........(Pythagoras theorem) and (all sides of rectangle are 90degree)

(54)²+(72)²=diagonal²

2916+5184=diagonal²

8100=diagonal²

90= diagonal.............(taking square root)

length of diagonal is 90ft

i hope it helps

have a nice day and thanks for asking this question

Answer:

-5.87,-33,0.5,17/25

Answer:

-33, -5.87, 0.5, 17/25.

Step-by-step explanation:

Thanks for the points!

Have a great day!

Stay safe and healthy!

Happy holiday seasons!

May I please have brainliest?

Answer:

48 minutes

30/5 = 6

6 x 8 = 48

Answer: 48

Step-by-step explanation:

if Tyreke can solve:

5 problems in 8 minutes

30 problems in ? minutes

(30*8)/5=48

Answer:

F(x)1/3x-7

Step-by-step explanation:

f(x)=(x-21)x1/

=/x-21

The number of items Shelby will donate as a function of x is f(x)=x-21.

A function assigns the value of each element of one set to the other specific element of another set.

A function from a set X to a set Y allocates precisely one element of Y to each element of X. The set X is known as the function's domain, while the set Y is known as the function's codomain.

Given that Shelby has x number of clothing items on her bed. She will hang 21 of the items in her closet and will drop off of the remaining items to a local donation center. Therefore, we can write,

Total number of clothes = x

Number of clothes she will keep in her closet = 21

Now, the function can be written as,

Function(x) = Number of items Shelby will donate

f(x) = x - 21

Hence, the number of items Shelby will donate as a function of x is f(x)=x-21.

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Answer:

16

Step-by-step explanation:

[3 x (6 + 4) - 22] x 2

[3 x 10 - 22] x 2

[30 - 22] x 2

8 x 2 = 16

Answer:

2844

Step-by-step explanation:

13 is to 12 as 3081 is to x. 13/12 = 3081/x. 12 * 3081 = 13x.

36972 = 13x. divide both sides by 13, you're left with 2844.

Answer:

210

Step-by-step explanation:

Answer:

x^4 + 2x^3 + 3x^2 + 2x + 2 = 0

Step-by-step explanation:

The computation of the polynomial equation of the lowest degree is shown below

As we know that the complex roots would always arise in the conjucate pairs

As -i is a root, i is also a root

As  -1 + i is a root

And, -1 is also a root

Now the polynomial equation would be

(x + i)(x - i)(x + 1 - i)(x + 1 - i) = 0

(x^2 - i^2)[(x + 1)^2 - i^2] = 0

(x^2 + 1)[(x + 1)^2 + 1] = 0

(x^2 + 1)(x^2 + 2x + 2) = 0

x^4 + 2x^3 + 3x^2 + 2x + 2 = 0

Answer:

Step-by-step explanation:

Radioactive dating becouse they look how long the fossils were there

Answer:

x = -84, y = -58

Step-by-step explanation:

2x - 3y = 6 --- Equation 1

Equation 1×5: 10x - 15y = 30 --- Equation 2

5x + 7y = -14 --- Equation 3

Equation 3×2: 10x + 14y = -28 --- Equation 4

I will eliminate 10x.

Equation 4-2:

10x - 15y - 10x + 14y = 30-(-28)

-y = 30+28

   = 58

y = -58

Substitute y  =-58 into Equation 1.

2x - 3y = 6

2x - 3(-58) = 6

2x - (-174) = 6

2x + 174 = 6

Find 2x.

2x = 6-174

    = -168

Find x.

x = -168 ÷ 2

x = -84

Answer:

y = 3x - 16

Step-by-step explanation:

In this question, we have to write an equation in slope-intercept form with the given information.

Slope-intercept form: y = mx + b

We already know our slope: 3

However, we don't know what are y-intercept (b) is.

To find this, plug the given information in the equation and solve for b:

-1 = 3(5) + b

-1 = 15 + b

Subtract 15 from both sides.

-16 = b

This means that our y-intercept will be -16.

Now, plug in our new information to the equation:

y = 3x - 16

The equation y = 3x - 16 will be your answer.

Answer:

y = 3x - 16

Step-by-step explanation:

Slope-Intercept Form: y = mx + b

Slope: 3

Points: (5, -1)

y = 3x + b

-1 = 3 ( 5 ) + b

-1 = 15 + b

b = -16

y = 3x - 16

Answer:

103.5%

Step-by-step explanation:

To find the percent change you will need to divide 621 by 600.

621/600 = 1.035

Multiply 1.035 by 100 to find the percent

(1.035)(100) = 103.5

Therefore, the value increased by 103.5%.

I hope this helps!!

- Kay :)

Answer:

103.5

Step-by-step explanation:

Answer:

hese angles are supplementary, and x=19 degrees

These two angles are a linear pair, meaning that they are supplementary.

This means that their angles measures must add up to 180 degrees.

65+6x+1=180

6x=114

x=19

Hope this helps!

Step-by-step explanation:

Answer:

17 remainder 25

Step-by-step explanation:

Answer:hmmmmm

Step-by-step explanation:

Answer:

5

Step-by-step explanation:

Rise over run... slope formula:

[tex]\frac{y^2-y^1}{x^2-x^1}[/tex]

x=0, y=0

x=1, y=5

[tex]\frac{5-0}{1-0}=\frac{5}{1} =5[/tex]

Answer:

It would take 6 years for the value of the account to reach $5,920

Step-by-step explanation:

Principal Amount = $4900

Interest rate r = 3% = 0.03

Compounded monthly = n=12

Time t =?

Future Value = $5920

We can find time using formula: [tex]A=P(1+\frac{r}{n})^{nt}[/tex]

Putting values and solving:

[tex]A=P(1+\frac{r}{n})^{nt}\\5920=4900(1+\frac{0.03}{12})^{12t} \\5920=4900(1+0.0025)^{12t}\\5920=4900(1.0025)^{12t}\\\frac{5920}{4900}= (1.0025)^{12t}\\1.21=(1.0025)^{12t}[/tex]

Applying exponent rule; [tex]a=b^c\\c\:ln(b)=ln(a)[/tex]

[tex]12t\:ln(1.0025)=ln(1.21)\\12t\:(0.00249)=0.19062\\t=\frac{0.19062}{12*0.00249}\\t=6.3\approx6[/tex]

So, It would take 6 years for the value of the account to reach $5,920

Given that,

y varies directly with x and y = 10 when x = 20.

To find,

The value of y when x = 15.

Solution,

[tex]y\propto x\\\\y=kx[/tex]

Put x = 20 and y = 10

[tex]k=\dfrac{y}{x}\\\\k=\dfrac{10}{20}\\\\=\dfrac{1}{2}[/tex]

Put k = 1/2 and x = 15 to find the value of y.

[tex]y=\dfrac{1}{2}\times 15\\\\=7.5[/tex]

So, the value of y is 7.5

Answer:

1 (240000)

2 (8000)

3(8160000)

Answer:

(4,5)

Step-by-step explanation:

Answer:

A. 8 3/4

Step-by-step explanation:

2 1/2 x 3 1/2 =

5/2 x 7/2 =

35/4 =

8 3/4