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2 years ago

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)

y=4

Step: Substitute 4 for y in x=−y+7:

x=−y+7

x=−4+7

x=3(Simplify both sides of the equation)

Answer:

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

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iVinArrow [24]

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Step-by-step explanation:

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3 years ago

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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

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^multiply the whole equation above by 3

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subtract the following two expressions:

3x - 3y = 15

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divide each side by -5

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take the following expression from earlier:

x - y = 5

substitute y value into above equation

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x + 1 = 5

subtract 1 from each side

x = 4

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3 years ago

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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:

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

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GalinKa [24]

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3 years ago

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

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