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3 years ago

Solve the system of equations. – 5x + 2y = 9 y = 7x X = Y =

Mathematics

2 answers:

Helen [10]3 years ago

6 0

Answer:

x = 1

y = 7

Step-by-step explanation:

Your system of equations is

-5x + 2y = 9

y = 7x

The easiest way to solve this is by substitution. This means that you set one of the equations equal to a variable and you plug that variable into the variable of the other equation. The second equation (y = 7x) is already set up this way so we will plug it into the first equation.

-5x + 2(7x) = 9

-5x + 14x = 9

9x = 9

(9x)/9 = (9)/9

x = 1

You have found x. Now, plug this number into the second equation (y = 7x) to find the value of y.

y = 7(1)

y = 7

Sphinxa [80]3 years ago

5 0

Answer:

x−y = 9 , x + y = 6

x + y = 4 , x − y = 2

x + 2 y = 4 , x − y = − 3

try out these examples?

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Dvinal [7]

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3 years ago

If a given data point is (1,4) and the line of best fit is y = 1.5x + 3.25, what's the residual value?

Svetlanka [38]

Answer:

The residual value is -0.75

Step-by-step explanation:

we know that

The residual value is the observed value minus the predicted value.

RESIDUAL VALUE=[OBSERVED VALUE-PREDICTED VALUE]

where

Predicted value.--> the predicted value given the current regression equation

Observed value. --> The observed value for the dependent variable.

in this problem

we have the point (1,4)

The observed value is 4

Find the predicted value for x=1

$y =1.5(1)+3.25=4.75$

predicted value is 4.75

RESIDUAL VALUE=(4-4.75)=-0.75

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3 years ago

Each pair of figure is similar. Find the missing length

ExtremeBDS [4]

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2 years ago

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A rectangular parcel of land has an area of 6,000 ft2. A diagonal between opposite corners is measured to be 10 ft longer than o

Drupady [299]

Answer:

50ft by 120ft

Step-by-step explanation:

Area of a rectangle = L × W

6000ft² = L × W

L = 6000/W

When a diagonal line divides a rectangle into 2 right angled triangles, the diagonal line = Hypotenuse of either of the triangle and it is the longest side.

The formula for a right angle triangle =

a² + b² = c²( c = hypotenuse)

We are told in the question that:

A diagonal between opposite corners is measured to be 10 ft longer than one side of the parcel

Let us assume the side that the hypotenuse is longer than = Width

Hence, the Diagonal = (W + 10)²

Therefore

L² + W² = (W + 10)²

Since L = 6000/W

W² + (6000/W)² = (W + 10)²

W² + (6000/W)² = (W + 10) (W + 10)

W² + (6000/W)² = W² + 10W + 10W + 100

W² + (6000/W)² = W² + 20W + 100

W² - W² + (6000/W)² = 20W+ 100

6000²/W² = 20W + 100

6000² = W²( 20W + 100)

6000² = 20W³ + 100W²

20W³ + 100W² - 6000² = 0

20W³ + 100W² - 36000000 = 0

20(W³ + 5W² - 1800000) = 0

Factorising the quadratic equation,

20(W − 120)(W² + 125W + 15000) = 0

W - 120 = 0

W = 120

Therefore,

W(Width) = 120feet

Since the Width = 120 feet

We can find the length

6000ft² = L × W

L = 6000/W

L = 6000/120

L = 50 feet

The dimensions of the land, correct to the nearest foot is 50ft by 120ft

3 0

3 years ago

Here is my question:

sergiy2304 [10]

Answer:

$\frac{2}{3} - \frac{1}{2} = \frac{1}{6} \times \frac{8}{9} = \frac{4}{27}$

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3 years ago