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lyudmila [28]
2 years ago
8

X+y=7;x+2y=11Solve by substitution steps must.​

Mathematics
2 answers:
Tpy6a [65]2 years ago
8 0

Answer:

Step-by-step explanation:

x + y = 7    ------------(I)

     y = 7 - x  ------------(II)

x + 2y = 11 --------------(III)

Substitute y = 7 - x in equation (III)

x + 2 * (7 -x) = 11

x + 2*7 - 2*x = 11

x + 14 - 2x = 11

x - 2x + 14 = 11

- x + 14 = 11

Subtract 14 from both side

-x = 11 - 14

-x = -3

Multiply both sides by (-1)

x = 3

Substitute x=3 in equation (II)

y = 7 - 3

y = 4

coldgirl [10]2 years ago
3 0

Answer:

  • \boxed{ \tt \red{ x = 3}}
  • \boxed{ \tt \pink {y = 4}}

Step-by-step explanation:

Step: Solve x+y=7 for x:

x+y=7

x+y+−y=7+−y(Add -y to both sides)

x=−y+7

Step: Substitute−y+7 for x in x+2y=11:

x+2y=11

−y+7+2y=11

y+7=11(Simplify both sides of the equation)

y+7+−7=11+−7(Add -7 to both sides)

<em><u>y=4</u></em>

Step: Substitute 4 for y in x=−y+7:

x=−y+7

x=−4+7

<em><u>x=3</u></em>(Simplify both sides of the equation)

Answer:

\boxed{\sf x = 3 \: and \: y = 4}

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noname [10]

Answer:

Surface area of the cube = 150\ cm^2

Step-by-step explanation:

Given shape in figure 1:

Cube with edge length = 5 cm

To find the surface area of the cube.

Solution:

The surface area of a cube is given by the formula:

Surface\ Area = 6a^2

where a represents the length of the edges of the cube.

For the given cube a=5\ cm

Plugging a=5\ cm in the formula to find the surface area of the cube.

Surface\ Area = 6(5)^2

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8 0
3 years ago
The histogram displays the number of 2015 births among U.S. Women ages 10 to 50 . Each bin represents an interval of two years,
iVinArrow [24]

Answer:

7

Step-by-step explanation:


5 0
2 years ago
Please Help! Show all the steps!
likoan [24]

You can start by subtracting different equations from each other.

3x + 2y + 3z = 1

subtract

3x + 2y + z = 7

2z = -6

divide by 2

z = -3

add the following two expressions together:

3x + 2y + z = 7

3x + 2y + 3z =1

6x + 4y + 4z = 8

subtract the following two expressions:

6x + 4y + 4z = 8

5x + 5y + 4z = 3

x - y = 5

^multiply the whole equation above by 3

3x - 3y = 15

subtract the following two expressions:

3x - 3y = 15

3x + 2y = 10

-5y = 5

divide each side by -5

y=-1

take the following expression from earlier:

x - y = 5

substitute y value into above equation

x - - 1 = 5

2 negatives make a positive

x + 1 = 5

subtract 1 from each side

x = 4

Therefore x = 4, y = -1, z = -3

I checked these with all 3 equations and they worked :)

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7 0
3 years ago
Which expression is equivalent to...? Screenshots attached. Please help! Thank you.
Studentka2010 [4]

Answer:

4x^{3} y^{2} (\sqrt[3]{4 x y})

Step-by-step explanation:

Another complex expression, let's simplify it step by step...

We'll start by re-writing 256 as 4^4

\sqrt[3]{256 x^{10} y^{7} } = \sqrt[3]{4^{4} x^{10} y^{7} }

Then we'll extract the 4 from the cubic root.  We will then subtract 3 from the exponent (4) to get to a simple 4 inside, and a 4 outside.

\sqrt[3]{4^{4} x^{10} y^{7} } = 4 \sqrt[3]{4 x^{10} y^{7} }

Now, we have x^10, so if we divide the exponent by the root factor, we get 10/3 = 3 1/3, which means we will extract x^9 that will become x^3 outside and x will remain inside.

4 \sqrt[3]{4 x^{10} y^{7} } = 4x^{3} \sqrt[3]{4 x y^{7} }

For the y's we have y^7 inside the cubic root, that means the true exponent is y^(7/3)... so we can extract y^2 and 1 y will remain inside.

4x^{3} \sqrt[3]{4 x y^{7} } = 4x^{3} y^{2} \sqrt[3]{4 x y}

The answer is then:

4x^{3} y^{2} \sqrt[3]{4 x y} = 4x^{3} y^{2} (\sqrt[3]{4 x y})

4 0
2 years ago
R-12 evaluate if r= negative 3
GalinKa [24]
If r=-3, then it would be -3-12 which equals -15
5 0
3 years ago
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